That honestly makes no sense since in nearly every raid I have been in for the last year, paladins have blown away priests in the healing charts. That should almost be turned around saying "lawl holy priest? if you wanted to heal, roll a paladin!"
Anyway, it is perfectly fine that you want to wear lesser armor values. Heck I wore leather boots until I was in SSC. If it has the correct stats, armor value really doesn't make much difference. One thing you need to watch out for though, spirit is a completely useless stat to healadins, and cloth/leather frequently stacks up on spirit, so you really have to be picky as to which pieces you use. Get stuff with Stam, Int, mp5, heal. You really are hard-pressed to find crit on that kind of gear, but you're not planning on using it for the rest of your healing career anyway. Get to 70 any way you can with whatever gear you can, then go down my sticky and start collecting that gear, then you'll be set to start hitting up the heroics and raiding.