I am going to use a "Twist Board" at one of my desks, and a compace elliptical at the other. Both desks are going to be converted to standing desks.

It's very feasible. I've been using mine for the past 2+ years. I also have a stool for when I get tired of walking.

Yes, it's the safetype (http://safetype.com). Much less wrist strain than normal pronating keyboards.