Just go frozen,,,,Silversides are a good food,,i use those and will also use Tilapia filets,,cut up into slivers,,,any non oily fish will work,,
Got a 180FO with "eaters" for fish in it,,,the oldest fish in there is prob 15 yrs old,(
snowflake eel-'bout 3 ft)and a
Clown trigger, Volitan lion,Porc puffer, etc. none of these have had "live" anything since i've had them,,(none of them are under 12 yrs in my care)
They will eat:
frozen anything(silversides/cube frozen/krill/squid/mussels/fish filets from the store etc.)
pelleted food
stick food(Tetra food sticks/cichlid food)
trout chow
all soaked most times in Selcon,,,
Don't worry,hunger will win on getting a "predator" fish to feed,,,might have to use a feeding stick on some fish,,'specially if the other fish tend to bother them at feeding time, spooking them away from getting food.
Some times i have to get my lion's attention b4 i drop food in,,he might miss it.
The sinking pellets i use (New Life,i think is the name) does not fall apart after hitting the water, so it'll last in the tank for a long time(1/2 hr) so my Clown Trigger has a ball looking for the pellets,instead of inhaling everything at the surface,,,,
IMO, i would not worry that much about keeping live feeders for your tank, spend your time/energy on getting your fish eating frozen/prepared foods,,,it'll be better in the long run anyway,,,