I kept clams and everything else under the sun under CF lights. However, I used 2x6700K and 2x10000K lights LOL. Man was that one ugly yellow tank! The problem as stated with the actinics is they don't do much, so your wasting 1/2 your lights. The T-5s are roughly twice as efficient and you can get bulbs such as the ATI that are basically actinics that promote coral growth. So, you are not wasting any bulbs for asthetics, making them even more efficient, in addition to the inherent approx. 50% increase in efficiency by going to a slimmer T-5 bulb with individual reflectors. Also, keep in mind, your saying the T-5s are $100 more, but remember, the your using 1/2 the wattage, which translates to around $50 per year in saved electricity. And the bulbs last a bit longer, and are a bit cheaper. So, really, I think you should look at all the costs, not just the initial cost, but that's my .02..
If you go with the PCs, You'll get better growth with less actinics, but the tank will look more yellow. 3x10000K and 1 actinic may be better. Or you could probably do all 1200OK, or a mix of 10000K and 12000K etc... just depends how much your willing to sacrifice growth for looks, which is really a personal call I can't tell you what is best other than that.
