Unfortunately, youre not getting much traction with this. People who can design are already doing this on shapeways and i.materialise (if not their own 3d printers) for much better quality prints and materials you might get from a home print. 3d printing a good product is more difficult than people imagine, its not so simple as pressing a button.

A word of warning too is you'd better be testing any parts you print (especially parts being clamped/structural) before offering print services to the general public. Failure can lead to serious injury and death.
I have designed mounts similar to the enve one for zipp, 3t , and deda stems; you actually need one of those stems to measure the dimesions necessary for the stem bolt mounting holes so unless you can provide those dimensions or your designer has an enve stem lying around you wont get it just by asking.