Help lighting a 24" cube

[noirsphynx]

Okay, so I need a bit of advice. I am going to sell my 90g system and I'm downsizing to a 24" x 24" x 18" cube which I'll have custom built and will be sps dominated. I'm getting a major headache with all the lighting options. I need something that's going to give me enough coverage and be good enough to keep sps alive & well but isn't going to cost me a fortune. I wanted to do all T5 (maybe try LED later on) but I'm having a hard time finding anything that's going to be more cost effective, it looks like they will have to wait and be a future upgrade(I've been looking at the ATI & Star Fire). I wanted to stay away from metal halide for heating issues and power consumption but I have the chance to get a Lumenarc pendant (250w de), will this suffice and how much a heat issue would you think I'd have(I just sold a brand new never used chiller :::smacks self in head::: and don't want to buy another)? I've also been looking at buying the fishneedit halide t5 combo lighting, I'd do a single 250w halide with a 2 x 24w t5 fixture on either side of the halide. What does everyone think? Any opinions or ideas?