Not to be bringing back thread necromancy, but I've been working on lights and electrical for many years.
VLED.COM is great for the price with every other color. However, I also feel their whites are a little bit on the "cool" side.
http://www.superbrightleds.com
SuperbrightLEDs.com's "Natural White" is pretty much the whitest 5k you can get with much tint of blue. It's up to you to justify extra $5 if you want the purest white you could get.