Well, the 55w 6000k will give you plenty of light, no doubt about that. With a 55w 6000k output you will be the same or brighter than a 35w 5000k setup so the difference is more than made up there.
The 5000k are the most pure white color, 6000k will have a slight blue hue to them but no way near a lot. I think if anything other than white, the 5000k lean towards having a slight blue tone.
