ryansmith83
or
aquaticeye
might know something about the compatibility of that many red tiger heros in your tank. Ive heard that curare red tigers are amongst the aggressive and largest of severums. You could possibly end up with a few breeding pairs wreaking havoc on each other once they are all mature. But im sure such fish would be easily rehomed/relocated/sold.
Love thinking about stock lists
Honestly too much of my brain power is spent on this subject. Including dreaming of it sometimes. The disease of the hobbyist.
Regarding the Rio Curare Tiger Sevs: I have found them to just just as docile and/or aggressive as the next cichlid. No more no less. That group size should work great in terms of group dynamics. The main thing that is an "issue" is that you'll be spending a lot of bioload on a single type of fish.
I had a group of 6 full grown adults for many years. At max size just be aware that these are big fish... they hit 10-12 inches. They got along well enough. I sold off 3 and I currently have 3. Again, they get along quite well together.
Now one thing to note is that tank size is always a factor in how things get along (or not). A 320G will be quite spacious (and congrats on such a big tank!!!). My group was in a 1000G so they had a lot of space.
Regarding other water level inhabitants... my votes
TOP:
1. Arowana; but personally I like aros
2. Chalceus group is a great idea; they are quite skittish though just keep that in mind
3. Hatchets are fun, but IMO get a group of archerfish if you're thinking hatchets; bigger and more interesting
MID:
1. Silver dollars are always fun. I think tigers are readily available and size wise do well in that size of a tank. Maybe mix in blackberries for some variety. Both of those grow to about 6 inches max and are reasonable. Most other silver dollars get TOO big.
* One note about silver dollars is that they tend to not be true mid-level fish. They are more low-mid. I have a 600G tank that is 40 inches tall and they're 90% of the time in the bottom half of the tank
