[QUOTE="Dr. Who, post: ..2 1 K's are kinda over kill.....A 5x5 is a nice set-up for 1 - 1K...[/QUOTE]
100% agree. 2K too much and you might get heat problems, or light bleaching.
2 600's or one 1K are sufficient, and you can always suppliment w/some quality CFL's for more horsepower.
Here is what I use for supplimental CFL,s:
https://www.amazon.com/gp/product/B005P29K1S/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
You can get them in both low and high Kelvin ratings. Not much heat output.
I'd go w/a 1K HID. Half the number of ballasts and bulbs to screw with.
I've got a 5 X 5.5 grow area with one 600 and about 500+ watts of these big boy CFLs. Kind of mixed and matched the CFLs with a few UV bulbs. Got 2 gooseneck lamps that hold 5 bulbs each, one of my best purchases, WalMart $23. So the goosenecks w/10 CFLs give me a lot of flexibility.