Yes, mine was over a 12 gal, and wasn't integrated into the hood. I think a 150w
HQI would be sufficient, especially that close to the water. You'd be able to keep just about anything you want up high in the tank, and probably lower light SPS such as montipora capricornis and digitata all the way tot he bottom.
I want to say the 150w DE bulbs are slightly longer than the 70w, but I've never seen a 70w bulb in person so I'm not positive. i can pretty much guarantee you're going to have heat issues with the 150 in a closed hood though. I'd strongly recommend a "clip on" like the viper or Coralife Aqualight, or a "stand on" like the sunpod if you're going 150. Either that, or look into a drop-in or probe style chiller.
As far as keeping the
PC lights, that's going to be personal preference. To my eye, 10k needs
actinic suplimentation, but I like the blue look. The corals will be fine with or without them.
