Oh ... hmmm, OK then. Guess that changes the advice then!
Hard to say then. The T5s-only option will give you unparalled options for mixing and matching bulbs to your taste. I don't see why an 8 lamps fixture wouldn't be more than enough for 30" of tank height..
But halides do a bang up job too. 5 lumenmax reflectors over that tank would be incredibly sharp.
Flip a coin I guess. Sorry I'm not much help, I'd be agonizing over the choice as well.