Thanks for the idea. I was thinking that if an actual company made one they would have some sort of support from bows, maybe plastic or wood, that would keep it from sagging. A local interior shop said they could make one for approx. $300. I thought not bad but if a company manufactures them on a mass scale it would be cheaper.

If I follow your suggestions and use some plywood, how would you suggest to attach it to the bed?

Thanks again for the help. This is my first hotrod and I need all the help I can get.