Bosus cost $100 and take up a lot of room. I think Cathe should do some sort of inflatible balance disc instead. I have one for a Firm video and it works great! It can be used for some intense crunches by putting it at the small of your back. 
Cathe is, by far, the best and I know she would come up with an amazing balance disc video.
Cathe is, by far, the best and I know she would come up with an amazing balance disc video.