For a 10g qt this should suffice:
http://www.marinedepot.com/ps_ViewItem~idProduct~ES53111.html It is a bit more light than you need for a qt, but there are ways to shade coral and/or raise the fixture if need be. The other is 28w version, but that might not be enough if you plan to keep them in qt for an extended period. You are not looking to maximize growth, but allow the animal to destress and look for unwanted pests or disease. Depending on the location of the coral in the initial tank (
lfs), you might see a shift in coloration of the coral being under
pc's, but that doesn't mean the coral is unhealthy either. The normal procedure for coral quarantine is that of fish, 30 days
**Oh, and I'm sure you could score a light such as this for much cheaper and even more-so if used