There are a few. Bluepacificsolar.com sold me my parts (17kW, 68 panels), engineered drawings and instructions. Roughly 33K, compared to the best responsible bid well in excess of $100K. Still, while its not rocket science, it is a big project. It took us 120 hours in labor over seven weeks to get it done. Because of the way my town issues permits, I was required to do the entire project myself -- I would have liked to have subbed out a couple of parts of the project (installing mounts on a 10/12 roof; final electrical connection, for example), but I was able to complete the project, exceed code, pass inspection, and actually look better than the less reputable bids.