Color temp depends on your preference. And the setup you choose.
If you decide only to go with pendants, most up the K to balance the color.
If you have MHs with supplemental T5s, a mixing of the options and use T5s for actinic supplementation most go with a lower K for higher growth rates.
However, in general the 10K will give you the best growth and higher K will give the "look" that you may prefer because most find the 10K too yellow, but at a cost to those higher growth rates.
By going with a larger wattage bulb from the get go, the loss in PAR you will get from a higher K bulb will not put you in the basement as far as PAR is concened, that is why I suggest 250's and not 150's like I had, after I put on the 14Ks on them my PAR was in the gutter.
Personally I just put on 2/250wDE MH 14K Ushio and have 2/96w PC over a 75 with SPS and love the color.
The exact brand and color of bulb is a completly different lighting discussion and very hotly debated.
However, we are treading to more of a light discussion that may be moved over to that forum very shortly.