shoot, get holy source gear and heal until the next expansion in it, i run around in t4 holy source healing GCH >.> but if you can manage to get yourself to 62, get a kawaks gown from kt, it's the next best thing to the redhill mem healing chest/annelias. less crit, but more raw healing. of you don't plan to level much on priest, or seriously consider healing, then yes, full holy source will do you wonders
as for stats, yeah, you should try for a crimson wis/hp, stam/int, and eother stam/int or wis/def, and then things with stam/hp/wis on the others. you don't have to worry much if your holy source hat came with a mdef/matt stat on it or anything, you can do pretty much anything with 3 crimson stats on your gear. though i can name a couple thing that i guess are out of the realm of likelihood... otherwise, you can prime stat wis/hp bunker, wis/hp crimson, wis/hp castle, hp/def bunker, wis/def crimson + one extra stat of your choice ( i don't use castles myself, so i go with two optionals and use an hp/mdef and int/stam) because at some point, you will go beyond what is needed in pve, and you'll never reach enough in pvp.