The wheeled Timberjack/Deeres have been around for a while, awesome machines. I had a chance to watch a feller/buncher do a thinning contract on Mt. Maxwell (SSI) on the property I lived on and helped manage (about 1999), darned efficient with a very small footprint, the bonus was all the free firewood I had access to afterwards since they only took logs 6" top diam. and over.
Now this prototype is something that makes them look like antiques> http://www.youtube.com/watch?v=CD2V8GFqk_Y&feature=related
*drool/slobber-slobber*
Shoot me some Prices on the units you are manufacturing. I would like to do some trading and even bring them in for our use if possible. I would even trade you out a couple of these cone heads if you want .