I'd go with a druid so you have someone to take +spell power leather. Plus, MotW is a nice buff, and you have someone that can stealth if needed. I main healed with a holy priest through all BC content through BT, and I think I could out-heal the druids but didn't have the versatility. Druids now have a regular rez (in addition to their battle rez) so that is no longer an issue. The only reason I'd take a shammie is for the self-rez (just don't wipe )