450-
Keep everything but really high-light corals on or near the bottom. If you're going with something uber high-light, still "screen" it for a week or so.
I burned my first Oregon Blue tort to bits 1/2 the way down with my T-5's.
You'll have plenty of light, even if you venture towards the blue side of the spectrum.
You need bulb/color suggestions? Have a Kelvin rating-ish in mind? I've been with T-5's since 2005ish. Would never go back to MH.
-Andy
PS: You'll love dealing with Aquatinics; great company for customer service, to boot...