Hello, and welcome to datnoids.
Hopefully I can get these questions answered for you here nice and easy and if you have any more please don't hesitate to ask.
To start one of the things that separates datnoids from a lot of other monster-type fish is their typically slower growth rate. I could go off on this in multiple paragraphs but to keep it short and simple I'll say this, there's no general rule that you can look to for datnoids in terms of growth rate. In my personal experience it seems you can generally get a 2" datnoid to around 7" in a years time though this isn't to say you couldn't do more or should expect that. In the past I've kept a number of tigers from .25" and up and I found that when I got them under an inch and got them eating right away growth was rapid compared to starting with a datnoid that was already a few inches long. The fastest I've experienced was one that was about an inch growing to just under a foot in a years time, this one fed on pellets almost from the get go. Flip side, I have a tiger now that's only grown from about 2" to 4" in almost a year on a similar diet.
Overall, the same factors for growth are in play with datnoids as any other fish, clean water, regular supply of nutritious foods, space and time. Just don't expect them to outgrow something like a SA/CA cichlid or most catfish.
Maximum sizes vary between species with
.IT and ST growing largest, as much as 2' in length and in some rare cases perhaps even larger (T1karmann's old ST) though 14"-16" tends to be more common unless you have a very large setup.
.NTT reaching around 16" though again, 12"-14" is more common, that said, NTT somewhat rarely seem to live long enough to see these sizes so a large one is generally a treat and a sight to see.
.NGT can reach around 16" as well though I've only seen maybe a half dozen online at this size with one possibly being slightly larger, around 12" is more common.
.AT seem to rarely exceed 12" usually getting around 8"-10". I've seen a small handful that possibly exceeded the 12" mark but my guess is that this is likely because most people mistakenly keep them in 100% freshwater when they would ideally be housed in brackish water.
As far as shipping I can't say as every datnoid I've kept has been purchased in person and I've never shipped fish in my time in the hobby. I don't believe you should have any problem though as they are generally hardy fish and I've moved datnoids in less than ideal conditions in the past. If you have access to straight oxygen to fill whatever bags you ship and have proper insulation them in you shouldn't have much to worry about from what I understand. Others on MFK could give you much better and detailed info on shipping if that's something you need to do in the future.
As far as housing with other datnoids, it can be done but it is advisable to have at least 3 or 4 if you have more than one. Reason being any potential aggression is distributed and diluted amongst the group. In my experience datnoids are generally not aggressive towards their own kind and other species alike though there are always outliers. Datnoids tend to form a pecking order in groups and aggression and fighting is usually minimal but it does exist. In my 180g aquarium for example I have two datnoids, 1 IT (10") and one NTT (4") (breaking my own rule of two I know lol). The IT has been the alpha fish of the tank pretty much since the day he was put in it about a year and a half/two years ago. He's dominant but not aggressive. He never goes after any tankmates and has had no instances where I needed to remove fish because of his aggression. The tank as a result has been generally one of my most peaceful tanks I've ever owned. He keeps everyone in line but never goes out of his way to chase anyone down or just generally be a jerk. I recently experienced a power struggle where a giant gourami of mine outgrew him and took over the top spot of the tank, chaos soon followed. The gourami was not such a peaceful leader of the tank. After trying some possible solutions and coming to the conclusion the gourami was no longer compatible with the tank I rehomed it and within a days time can you guess what happened? The IT reclaimed his spot as the dominant fish in the tank. No aggression, no fin nipping, no chasing. One theory of mine is that datnoids may not feel the need to defend and fight for territory the same way some aggressive cichlids might as they are much more of an ambush predator and typically will remain in one area idle waiting for the opportunity to find food where as other larger predator fish like cichlids and such will more openly wander to find food therefore needing a greater territory to access those food sources.
I would say as long as you house them with fish that aren't overly aggressive and territorial and won't end up in the menu you'll be alright. I have a 180g with the two datnoids mentioned above along with an 11" silver arowana, 17" black spotted eel, and two 3" striped silver dollars. I plan on adding a group of baby tigers that I'm currently growing out down the road though at the moment they're all around 1" long so that may take some time. Fun fact(sorta) datnoids are one of the few species who seem to not predate on their own kind. I won't say it's never happened but I've seen and in my own experienced datnoids around 2" in size with datnoids over 1' and it seems they just don't eat one another. I'm sure if you look it up you can find some interesting threads mentioning it here from a while back.
The price you mentioned is a little steep but when it comes to ST you're not going to find one that doesn't carry a steep price tag and considering the going rate as crazy as it sounds, it hurts me to say that $1000 for two ST at that size is a pretty amazing deal. Not disrespecting but are you well versed in telling the difference between IT (specifically 3 bar oddballs) and ST? If not I would gladly help you out so you can make sure you're getting a fair deal. I've seen many IT sold as ST in the past and in most cases it genuinely came down to the seller not knowing the difference between them and unfortunately they had been had bringing in the fish at the price they did. Put it this way, I'm kinda broke right now but if I had an ST at 2-3" offered to me for $500 you can bet your ass I'm finding $500 that day.
**going back and rereading your post you mention it's unstable, that's an immediate red flag in my mind. Is it possible for you to get a couple decent, even semi well lit photos of these supposed ST?**
Lastly, the fish you currently have would generally be just fine to house with a datnoid aside from the angels. Not saying it would be a nightmare but They're generally slightly fragile fish physically and a datnoid can grow quite boisterous and large and I would think in most cases long term it wouldn't be the best fit. aside from that it seems ok on paper. Also the obvious and not trying to sound disrespectful but a larger tank down the line would be for the best. that said, I have a 180g and I'm starting to thing it's looking small after just two years, I know we're all crazy fish people to the rest of the world but you could give me a 1000g aquarium and I would still look at it and say, "mmmmbigger is always better.." eventually lol.
Anyway, hope you find this helpful and again, if you have any additional questions or would like further elaboration on anything please don't hesitate to ask.
