you better turn tempest and try to reach a good lvl like 85-90 , most of the players what have radiants do that (even if there is ever some "purists"...hehe) cause yeah finding a team or players willing for teaming can be hard theses days , and yeah a "pure rad from the beginning" unless you make a "pew pew" rad and make a reset skill when you hit high levels...knowing that reset skill is a payable item (by item mall) but that you can have sometimes events like the one what was running theses last days, with npc selling job change for example.
bad thing is : don't know if the npc will still be there after the actual maint. and so you may have to wait a long enough time before next opportunity if you don't want to pay.
on other hand here is the list of the classes with "healing/support" abilities ( if you are the healing type as you said)
- as said rad , of course
- tempest have one heal they can send to only one player a time with a medium recasting time
- protectors can be good at heals : one party heal that can do the half power of a rad on a average toon , and a single targeted heal (+ a lil HoT that can't be counted cause stay personal -same on tempy)
- mystics , that can be insanely OP in pve (and most of the time in pvp too - i think each player in the game have at last one mystic, yeah not original , but hell : efficient) you can do with that class in pve what you can't with most of others (except maybe prots but you will take X359 more time , ah ah ) (or defis if you are good at running and with a good vampiric touch) they have a healing totem that can make very decent HoT and cancel DoT + a personal small HoT + a single target heal + a heal party (AND they can do good damages even with low stuff AND they have a defense totem...did i say OP ? naaaaaah , ah ah ah )
- elems have three heals too , but weak enough , only two can target others (and single target) the party HoT is kinda weak. as it is first job skills , technically druids benefit of it too , but druid is actually a broken class , better not pick that for now...for info , elems have some nice and appreciated party buffs too
i think i don't forget much here... just didn't specify about party buffs tho. hope it will help you