Do your suppliers need to modify your drawings or just view them? If it's the latter, then try looking at Volo View (it's provided by Autodesk). Volo View is a program that allows non-Autodesk users to view your work, as you see it in Inventor. This program should be on your CD, or you can download it from Autodesk (or simply Google search for it). This should help simplify your problem...maybe. 🙂
Anthony Gleaton