Yep, it can be done. You'd need the belts, attaching bolts and matching trim pieces to bolt everything in. The problem is, I think it's illegal for a wrecker to sell used seat belts. But it can't hurt to ask! Just go to a local dismantler and ask if they'll sell the parts to you. Maybe they won't car(or even know about that stupid law).
Think twice!!! I have automatic seat belts and they do work great! Also they are real seat belt ticket savers! I was stopped a few times by police, and although I didn't have a lap belt buckled up - never get a ticket or worning! After avile you'll get use to them, and like them.