Jon,
Go to your local autoparts store. Tell them you want a Dorman 610-323 wheel stud. This is a M12-1.2 X 54mm stud that is an overlength GM replacement (believe it or not) It presses right into the hub with no modifications and gives you PLENTY of length. Keep them lubed with fresh antiseize and you'll have no problems. I have even run them with wheel spacers and no hubcentricity and they worked fine for the season (not usually recommended though). They are cheap and fit great.