I have kept many frogfish before.
Personally I do not like feeding freshwater fishes due to the parasites etc in them, although its the most affordable feeding method.
I know this may sound bad, but i actually feed damsels and chromis to my frogfish.
Frogfish is a interesting species, and they are very beautiful imo.
If you have a refugim, you can even keep it there. Just make sure the pumps are hidden nicely to prevent the frogfish from being suck in.
Alternatively, get a nano tank or just a simple set up. Anyway if your tank too big, the frogfish might have problem catching e fishes.