I'd go with the 6000k to be honest.
You get rid of that "yellowish" hue that many people complain about with 4300k bulbs, but don't go too far off into the blue range. That, and your light output will be better with 6000k vs 8000k. The 6000k bulbs still have a slight blue tint to them.
Get the Phillips Ultinon 6000k bulbs. Great quality, although definitely on the expensive side.