does any one know where to find some aftermarket wheels for a dully?

How about some big wheels (http://www.ricksontruck.com/wheels_gm_drw.html) :ro)

Alcoas (http://www.alcoa.com/alcoawheels/north_america/en/light_pickup_dualie.asp) Seem to be real popular too.

weld (http://www.weldracing.com/Weld_Racing/wheels/f1_dually.shtm) Builds a few models.

Hope that'll get you started, there's a lot more out there just gotta keep lookin'

www.brentzwheels.com 17,19, 22, 24, 19.5 all available direct bolt on no adapters needed. also www.rickson.com has the 19.5 as well.