Ray, if you go with a retro set up you should be able to fit 6 with no problem. Ice Cap slr reflectors are around 2" wide each - and they are still one of the best on the market for T-5's. Yes, you don't get the same shimmer as with halides. I've never ran halides so I can't say that I miss it. I have been around several tanks that run halides and I know my tank runs immensely cooler - not just the tank, but the area around my tank also. You can try the T-5 thread over on ReefCentral - There were around 40 pages on just T-5 lighting last time I looked.