I'm not sure any of them are right; bulls are hard to pull off well, unless of course you're Vince.
Jim hasn't had a whole lot of development; in fact, he's only appeared four times that I can remember:
My basic thoughts about his personality are that he's not hostile, but he's not especially friendly, either. All he cares about is putting in his 8 hours and getting the work done. Anything that facilitates that makes him happy, anything that interferes, annoys him. Everything else just sorta goes by unnoticed. I'm not sure if he's defeated by life, or just dreadfully dull.
#1 is the most middle-managerish, but he seems a bit complacent. #4 is the most appealing character design, I think, but he looks too paternally friendly in that pic. #3 has about the right attitude, but has some pretty major anatomical flaws. :) This bears thinking about a bit. I think I'll head off to bed and approach it fresh tomorrow. G'nite all!