Need help sourcing out power seat parts...

I have a 96 Z71 Ext Cab with the six way power seat. The passenger side is manually operated. I need to know if anyone has these parts available whether new or used and what you would want for them. Also, if anyone knows any web site, or local business in your area that could get me a good deal. The part #'s are GM: 15975329 Power seat assembly, 22543666 Power seat adjuster switch, and 15991498 passenger seat outer track/riser assembly. Thanx -Chris