AI's no good for Flowerhorns (they've got 'em but I don't suppose it would be of any good quality). U're better off looking at those 'only flowerhorn' shops... (Plenty around.)

I don't know very much about the flowerhorn, other than it is a hybrid fish of possibly Trimac and Red Devil lineage. That would give a hint of their temperament and size. They get LARGE (as I suppose you know), are highly aggressive (hence you don't see 2 adult FH's in the same tank.... unless they are breeding or something.), and are messy feeders.

Firstly, u'd be looking at getting a nice big tank. 4ft tank would be an idea for 2 FH fish (separated by a glass partition of course!). For tankmates, u'd most likely be looking at a pleco (aka 'bandaraya' fish)..... or if you'd get a bigger tank like 5-6ft tank, then possibly an arrowana, a large catfish, or some other big fish. Anything fish smaller than it would be conveniently turned into a play toy if not dinner. Filtration would need to be substantial especially if you're thinking of feeding life food like guppies or shrimp. For a 4ft tank, I'd suggest at least 2 box filters for 2 FH fish.

Also, make sure you read up about cycling a tank b4 u add the fish in (ie about building up bacteria in your filter b4 putting the fish in.). Make sure your tank is properly up and ready and the filters have been running for a while b4 you go out and buy a whole lot of fish. Not good Karma (dunno about Fung Shui) to go killing fish....

Good luck.