I have one and it is kept with bichirs so the answer to your first question is yes.
But first which species are you planning on getting? Only the Coius (Datnoids) microlepis is a FW fish and other species of STF are brackish fish.
They are greedy eaters and once they have settled in will take all manor of live and meaty frozen foods, they will eat any tankmates less than 3/4 their size. They are easily frightened by fast or sharp movements outside the tank and need cover in the form of plants and rock/bogwood for them to hide in and behind. Be aware that they can grow to 16" (but slowly) and at some point will need a very large deep tank.
