I would definitely go with a galaxy ballast, they are electronic, work on mogul and HQI, affordable and the performance is second to none in my opinion. I use a galaxy ballast with my 250W HQI on my frag tank and love it. As for a bulb I would see if phoenix makes a 14K in mogul as the HQI bulb I have is nice and blue and crisp not to mention really reasonably priced.
Heres a pic of my frags under the 14K Phoenix bulb
