This is a pretty good example for you. It says -20 offset to get the 295/60/20 to fit without rubbing, and it looks borderline if you would need flares or not, that would probably depend on how many gravel roads you run.
Another option is the 285/65/20 BFG's. I have them on stock rims and they look really good. I wouldn't mind a bit wider, but they look good, don't rub, ride well, and don't need fender flares.