did you check out gravograph yet?
they're quite close to you and i'ld expect them to know what you need as well as understanding you are a jeweller and not 3d cad cam programmingwizard.thus their machines might be esier to learn/operate.
but if you can and you want and you need to do the very nicest jobs and know how to operate one i'ld easily vote cybaman for any jeweller !
if your gonna build one yourself i wish you much luck.
Finally CHIPS you can have as much as you can without the doc. complainting about your cholesterol.