For the driver side I would just put up a post in the car parts wanted section for one. Some one on here will have one in nice shape for you. I sold the two I had for $5+shipping.
The pass side is a little harder as it is connected to the heater box and they go for around $100+shipping. But again I think if you put a post in the car parts wanted section some one will have an old mabby even broke box that they could sell you the door and hinge off of for a few bucks then you could just rivet it on to your box.