I personally went with the 5000k HIDs. Bought from Gary (protephile) and they look damn great. I was looking for pure white (no bluish hue) so I picked the 5000k. Easiest install ever, took me 20 minutes, 10 to find the best place to put the ballasts and 10 to do the actual install. Bought them for $200 during the group buy, I think he has them for around $230 now, not sure though.
If you choose to go with Garys Techone HID kit, here are some install instructions, Rush did a great job with this.
http://www.mazdas247.com/forum/showthread.php?t=123642902&page=25