Hi there Doowhip - I am looking for a 4th core healer for my raid team. Honestly any of the classes you listed would be fine, though I am mostly intrigued by the hpally or resto shaman - I think they offer a lot of utility to a raid team that our comp currently lacks outside of the raw throughput that evokers and resto druids provide (which is what we have already).
I’ll share our guild post for you to look through - it includes my BNet if you’d like to reach out to chat further.
Best,
Liim
https://us.forums.blizzard.com/en/wow/t/assault-aotc-guild-thufri-evenings-lfm/1540588