Personally I would make sure you have at least 4 coral+, I think they look fantastic and have plenty of blue in them. Purple+ really adds red so I only use one of them. In my 6 bulb fixture I' using 3 coral+, 2 blue+, and one purple+. I also supplement with one BML 20K strip light.
The ATI fixture has fans that blow on the cool spot in the bulb (make sure to put the labels on that side) and the air then moves down the length of the bulb and out through a gap on the other end. PAR on the 60" fixture is nothing sort of amazing. I'm at 200+ down on the sandbed in my deep but narrow tank. Bulb life with the ATI should be around 8 months based on what I've read. Considering each 60" bulb is only a few $$ more than the shorter bulbs the 60" really saves money on the bulb cost IMO.