I picked up an IceCap 660 and 3 sets of end caps yesterday. I'm planning on using T5s to replace my PC lighting. I know I need another set of end caps, but I'm not sure which bulbs to get or where to get them. I was thinking of using 2 10k bulbs and 2 actinic bulbs to start with. I'll probably get a second ballast for the actinic lights and put in 2 more daylight bulbs, but that's in the future, somewhere.

Any thoughts on this? What types of corals could I keep in a 90 gal with a 4 bulb T5 setup as opposed to a 6 bulb?