Replacement seat belts and air bag

My car was hit in the front end. Not too hard but enough to have the driver's side air bag activate and both seat belts tightened up due the pre-tensioners activating. I need to replace the seat belts and air bag. Will the aftermarket seat belts that I see for sale on ebay work and properly interface with the car's restraint system and computer. Has anyone used aftermarket seat belts? Are they direct replacements? Thanks for your help.
Bob