I dispute your premise. As a prot paladin, you don't need to beef up avoidance against melee. Our spec excels defending against melee. Defensively, what we need to worry about are casters - so we need resilience. But more than that, what we need to do is to beef up our damage, which is lamentable. So gem strength. That's our best threat stat (get 5% hit too though). Either pure strength all round or go strength/hit and strength/crit for socket bonuses.
If you did want to gem "avoidance", I think mastery would be better than dodge or parry. It's not avoidance, but converts to less incoming melee damage per item value than do true avoidance stats. But to reiterate my main point, gem mastery for PvE, not PvP.
Look up Taugrim for a nice Pally PVP blog. There's a threat on that subject in the offspecs sub-forum of maintankadin.com where he has recently posted and gives the link for his blog.
PS: not sure why this thread is in this archived forum.