With that level of depth (36 in) you could get a setup where the first third of your tank was comprised of SPS, LPS in the middle, and low light corals toward the bottom, but at 36 inches they will likely have to be pretty low light. I've not done MH, but they seem to really get the job done if you have the space and the ability to dissipate that heat well. Beefed up LEDs could do the job. I'm completely clueless as to whether T5s would penetrate that depth well (but the top third would do well), and I am leaning towards "no". If budget was no issue you might consider some sort of combination (they sell T5/LED) "racks" where you can augment your LEDs with T5 for color/dispersion. Again, budget is what it comes down to.