Questions for CFLs for side lighting

I need a few CFLs for side light. My plants are getting large and some of the side leave are drooping. I think they're not getting enough light as a small canpoy is starting to form. I have one 1000w hps doing most of the lighting. I was planning on getting 2 hanging ones. What is the difference beteween 2700k and 5500k, 6500k and which should I get? Thanks. Ill post pic of the plants later. Most seem to be doing very healthy exept some of the bottom leaves on some.

I know Im late but it depends on what stage of growth ur in. The 5500K and 6500K are best for veg and the 2700K are best for flowering.