Definitely an option - they have aerobic steps you can buy. I'd be extremely leery of any coffee table at my current weight! and the idea is to have the exercise equipment in the bedroom, hence the need to downsize.

Although what I'm considering at the moment is just getting rid of one of the bikes completely - if we want to work out together, there's the Wii and the Kinect (and, now that you've brought it up, a step of some ilk).