Tough call -- its all about personal tastes... Also -- kelvin rating isn't a fair way to judge what you're going to get, its a guess at best... Every brand has a different appearance to their color. I'm running Phoenix 14k's, and I'm quite fond of them -- very crisp white light, but good fluorescence from corals. Reeflux 12k's have a huge following -- anything 20k is VERY blue (think mild actinics)... Search for Sanjay's site of Metal Halide reviews.. he's got average PAR ratings and great explanations of what to expect -- probably be your best bet without just checking out lights in person..

-Justin