I don't think Trumpets need huge amounts of light, about the midpoint in your tank would probably be fine, although with VHO, you could put them all the way up at the top if you wanted. When mine was only under VHO I had it about 3/4 of the way up.
They are little oinkers and will eat just about anytime you feed the tank. The more they eat, the more they grow

I feed mine small bits of whatever the tank is getting. Silversides, blender mush, frozen cubes, bits of krill or prawns, brineshimp...they aren't very picky as long as it smells meaty.
Good luck with yours!
Alice