If you're planning on playing healers, you've got it backward. Knight/Priest and Warden/Druid are both tanks. Priest/Knight and Druid/Warden, however, are both healers. Stamina, physical defense, HP, and wisdom are all common stats for healers to use.
As for wisdom, priests have a very low wisdom cap, in that past ~8k wisdom, it will not increase their heals any longer, so priests usually use only one, if any, wisdom stat per piece of gear. Gear itself gives a lot of wisdom, and runes can as well.
Druids have higher wisdom caps on their burst heals, and HoTs (heal over time) don't have wisdom caps at all, so stacking a bit more wisdom is helpful, though the only druid combo that actually needs to go wis-crazy is Druid/Scout. Other druids, it's really personal preference -- but a lot of D/Wds I know tend to stat more like P/Ks, with just a little bit more wisdom, due to the pdef buff.
Intelligence and magic attack do nothing for heals. Priests technically could sacrifice some survivability (or wis) for Int/Matk fillers, but most don't. Most healers, whether druid or priest will go purely defensive in statting (and/or wisdom-intensive, for some druids), and make a secondary set for offensive stats if need be.
