Macbook Body Replacement?

I have a Macbook from 2008 which is awesome, I like it alot, but it is kind of beat up, some cracks and chips on the brittle inside of the body and more. I would like to buy one of the new macbooks but with no computer inside, I would just put my own it, I'm hoping that since I would be buying an empty new computer it would be a very reasonable price. But I can't find a place to buy one at. I've searched macbook shells and body etc but all I find are cases, so if anyone knows anything about what I'm trying to do and where I could purchase one of the macbook bodys with no computer in it, I would really appreciate the help!