I can't see doing any welding unless all is stripped down to the metal frame.
Most of my components came from Dr. Rebuild, including all new nuts, bolts and screws. I do not know his supplier but the quality is very good. The hockey sticks were re-chromed by a local firm specializing in custom Harley-Davidson work.
A local auto glass/upholstery company did the actual installation. Things were dismantled to the frames, those were cleaned and painted with rust paint, the headrest brackets were welded in, and new foams and covers installed with all new hardware. The cost was $350CDN, about $300US at that time (March 2004). I felt that that was a reasonable price to pay.