Paula, there are a few forums that talk about the Gemini. I have a Revolution Grand, as do several others. You may be able to do a general search with "Gemini" and find them. You can also look up member The Neutrino Group. Jason is the one to talk to about the product options and sales.
I would love to talk to you regarding how the Gemini reduces, if not eliminates, the thumb issues you speak of, as well as upper back and shoulder girdle stress and wrist pain and numbness along the pinky side of the hands.
You can email me at: email@example.com or call me at my call: 714.349.7724.