BoostLED & Par 30/38 bulb questions

I have a question for the light experts out there. I am weighing options on expanding my lighting and coral selection in my 75g. As it sits now I have softies & a few LPS under a 4 x T5 set up. I was leaning towards LED options and reading about the BoostLED lights and would like to envision some SPS further down the road. I am a little confused on how many I would need to go the length of a 75g tank. From my grasp of is they cover a 12x12 area but would they cover the depth of my tank? What about the spread, and what angle of reflectors would I need to look into? I know the MH fans will say go that route, but a MH fixture is pricey when I factor in bulbs and so forth in the long run. I know a MH DiY would be cheaper than a fixture but I like the open top look vs building a canopy. I think the boosted's if they work along with some sort of track fixture could produce a nice clean look.

 

Orphek make a PAR38 type fixture more suited to this application called the PR25. According to them it gets better spread than a PAR38 and they recommend it as more of a light then a spotlight. Link: http://orphek.com/wordpress/?p=341 just sounds better for your application. I would say 4 or 6 par38 bulbs, 6 would probably be better for SPS. Optic angles are something to consider.