The optimum colour temperature is around 5000k, which is the closest to natural daylight and produces very little glare (providing you don't have them pointing too high). Anything higher than 6000k and you're sacrificing looks for useability.
Are you going to keep the existing headlights without the projector lenses, or upgrade? If you stick with the halogen headlights you're going to cause a lot of glare in any colour temperature.