Here's Shaver's Home page. I requested a brochure from them on the stump buster and they sent me brochures on all their products and a video of the stump buster. I was impressed.
Here's another but for larger tractors. I like this one. /forums/images/graemlins/cool.gifStumper 3500
I don't mean to turn you away from your choice but to inform since I spent a bit of time researching this awhile back.