A priest who's at least 41 into Disc is probably going to be best for 2v2, though a 28/33 is still probably pretty formidable (and more capable in 3v3/5v5 imo). The angelform, crit immunity, and healing through crits is nothing short of godlike with good PvP gear. My 5v5 team (MS warrior, DW fury war, lock, me, holy pally) can burst down a holy pally with another healer on them fairly easily, but a 28/33 priest is brutal... and they keep healing after they're dead.