Hey JMF, I didn't see this thread before I posted in the other one, but there IS a way to get this done! (Check the other thread)
Since you are looking at buying a rig though, it might be wise to buy a cheaper rig and upgrade. This is pretty common in the Steadicam industry, simply because most parts are quite interchangable. The theories behind the device are incredibly complex, but if you don't mind doing a lot of playing around and not having a rig that is 100% a copy of the big film rigs, you can really have a lot of fun and get a really nice rig going. Also, a good thing to remember is that whatever choice you make, weather it be to homebuild, get the Glidecam, or get the Flyer, It's all about the operator. If you don't know beans about stabilizers, you will be a bad operator no matter what rig you get. Even the best rig can't make you be a good operator. It takes a lot of practice and work, but trust me, with enough work even the most consumer of rigs can work very very well.
See ya later.
-Tom