I have several, but they are pretty pricey. I have 3D Studio MAX 5, which is great for designing stuff for computer games, then I have AutoDesk Inventor, which is perfect for creating concept pieces and 3D renderings of specific parts, then there is AutoDesk Mechanical Desktop, which is pretty good for 2D stuff. I also think have a copy of AutoCAD Architectural around here somewhere, but I'm not sure. The last one I have I believe is called CAD 2000. The licenses for these are pretty expensive, and I'm afraid I don't have a program to suit your specific needs. These will get you by, but I would have to get more detail on what you want before I can make a specific reccomendation.