Great initiative there amigadave and good luck with it.
Im sure I dont need to tell you this, and its good to see you have a reasonably safe criteria, but Id advise a little caution. Ive seen it many times with these sorts of initiatives over the years that some people with no real knowledge (but enough to sound convincing to those with less) take advantage of this sort of thing, only to never contribute anything back other than a few write ups and excuses after theyve received their machine. Not to say there's a deliberate intention to deceive, but some peoples eyes are bigger than thier brains
(that's to say their interest in what's offered outweighs their ability to deliver).