Simon, no, you cannot permanently increase anyone's wisdom in the game other than by cheating but that doesn't really matter, as most priests in the game have moderately decent WIS.
As for making your character a monk, why not play the game through with your figther character first, so you can get to know the game, and then play it a second time with a monk (or anything you like). The game's so replayable that you won't be bored.
------------------
Melusine, Archbabe of the Order of the Holy Flame and the Laughing Hyenas, &
Official Entertainer Elf of the BG2 Bar
Your voice is ambrosia