Good guide for Paladin pre-raid pre-heroic crit immunity. I am not sure how much HP this will give you though. A bit pricey with the BoE epics and I know you said you don't have a ton, but with 5 L80s to run dailies or grind with you should have no problems affording this stuff.

http://wowthinktank.blogspot.com/200...crittable.html