suggestions needed for t5 setup

[smokinreefer]

hey guys,

i've always been a MH guy, but i'm looking to switch out my MH on my nano for some T5s.

i'm currently running a 250W DE MH, and a couple thing i'm hoping to resolve by switching to T5s are:

-the single point light source of the MH is fairly distracting and harsh on the eyes with the tank being in the living room. so hoping the T5 fixture will have a "softer" more diffused appearance.

-i've heard T5 run quite cool, so hoping that will alleviate heat issues and allow me to decommision the chiller.

also any recommendations for fixtures? i'm lighting a Current USA Cardiff tank. the tank with the rounded front. its footprint is about 20" x 20"
i'm wanting to get a 6-8 bulb unit for it, thinking i'll have to go with 24".
so far i've only come across one 8 bulb unit, but its the sunblaze and i gather that its a very low end fixture.

one more thing, i have several clams in the tank, and a few sps frags. so i want to be sure to provide them sufficient lighting.

thanks for any input!