will the ss wheels fit a 2002 2wd. and is there enough clearance for those and stock tires to fit? and where is the best place to find ss wheels? will any 4wd wheels fit a 2wd?

Yes SS wheels will fit. SS=AWD.

Yes, in 99 Chevy changed all half ton pickups to have the 6 lug pattern. So all 4x4 and 2x4 1500's have the same pattern. Before 99 2x4 had a 5 lug pattern and 4x4 had 6 lug.

Any 99 up silverados should take the SS wheels, as well as escalade, and GMC.

You can always find them on ebay or if you know a customizing place they may have some.