As long as it is fish only, it should just be a matter of personal preference as to what color light you like best. The higher the number the more blue the light will be.
I want to say I read something that said you need 3-4 watts per gallon for the live rock. As for the color temp, I think it will still be personal preference. I use VHO's with one 10,000 K and one 50/50 actinic.
the lower the degrees kelvin, the more yellow the lights will appear... there's a great page on lighting in the archives that explains it really well if you're in the mood to understand it. lol. i had to read it twice. it's called lighting 101 i believe. definitely worth reading!