Wanted parts for 87 Chevy R10

[greenhorn male]

Where could I get the best deal on a new dash pad, body molding, and seat belts for my 87 Silverado Short fleet.
Also the velour upholstery on my bench seat is ripped. I have a velour type seat cover which looks nice but wouldn't stay on. What would you suggest, or what have you done in this case? Purchase an upholstery do it yourself kit (from whom)? Have it professionally upholstered? Install an aftermarket or later model seat? Thanks for your help.