your T5s should be plenty. I have a little 46G in my bedroom under T5s that chalice frags are doing very well in. I'm using 2x aquablue and 2x actinic plus in that tank.
My bigger pieces are in my display under a whole lot of light....but they are close to the bottom, and the tank is 30" deep
I have a couple random chalices in my sps tank close to the top under 400W halides and high flow that are still doing great. They seem to be very flexible.
I haven't ever tried to feed them, though I've seen them try to grab a piece of mysis now and again. I imagine you could spot feed them with phyto, or cyclopease.....but I don't target feed mine
~D