T5's will give you a pretty good result, especially for the amount of money you're going to be spending on them compared to metal halide. MH lights are almost always gonna give you the better result...but they're also twice the price or more. IMO, go with either a MH setup or a T5 setup (or even a combo of both).
If you could suspend your lights above your tank (via either legs or suspended from the ceiling/overhead fixture), the center brace won't be a problem. I'm with you, dremeling the thing would be my last resort.
It sounds like you pretty much know what you're doing....good luck
, and keep asking questions!