Pond shield is the go-to option from what ive seen. I think theyre one of the only ones that actually advertises use for ponds, etc. and since it does, probably has a markup in price over competitors as well.
You might have a hard time finding something that advertises "aquarium safe". You would probably have to do a lot of expensive research before making that claim, and companies just dont want to pay for it or else have the liability on their hands if they dont. So while they might not advertise it, i would theorize that most if not epoxies were safe once they had completely cured. Imo though, if i was doing it, id probably just reach for the somewhat proven pond shield.
There are plenty, plenty of build threads here with different epoxies than pond shield. The thing is theres not very many of them that display the tank over time, or show the tank operational very long after its construction, so we dont get a lot of "proven" reviews.
I think youre talking about sealant coatings for granite or quartz and whatnot??? Im not sure, definitely dont remember ever seeing it used in a tank build.
Never seen that particular option on your list either. Is that the epoxy you plan to use?