One of them (that I won't disclose just yet) seemed very interested in the project and they would be able to help us in the whole process. Talking with them we agreed that we could run a test "keyboard construction kit" for a numpad, and if everything goes smooth we could expand to a full keyboard. Price would be extremely attractive.
So if there's enough interest we could have a very high quality numpad with whatever layout we want. Being smaller we could even try to have the case CNC'd! It would be still a DIY kit, but you'd get everything you need, and the quality would be high-end. Also I may be willing to offer an assembly service if you need it.
These are the preliminary designs, but I'm not an avid numpad user so I'd like to have your feedback!

blanks of course could be anything.
Ideas? suggestions? impressions?