Sadly, I think this is just not possible economically as well as technically.
Unlike cellphones which are sold in the 10's of millions of one model, digital cameras are sold in 20,000 to 50,000 per model. So finding all of the needed parts for a single model will be almost impossible unless you're in Asia where the camera you want is made. Even getting reject parts will be costly! So lets take a different approach locate broken cameras on eBay and then build a working one that way. Again you'll likely need a good half dozen to build one working camera still too expensive!
So that leaves us with just finding a good working used camera as being the cheapest way.