Which CPU for crunching large Images

I would think that the software would sort of suggest which cpu you will need as in is it multi core aware or not,once you have acquired the software check the packaging ,should have recommended specs,or, go to the relevant forums.. 

And don't forget a system with as much RAM as possible for working on huge image files.

+2 !

Well i Know that if its Adobe Photoshop CS (or up) it supports use of the Graphics card, and quad core, so you might want to factor that.

what Flakes said and ++++1 for RAM lots of RAM, Vista64 if need be and TONS of RAM, this is one of the situations where more RAM is always better

Intel Quad with at least 4GB ram on a 64 bit windows.

core i7.

Core i7 + max RAM + latest gen video card = ftw!