Your best bet for a skid loader mounted grinder would be a miller pro/diamond like f311fr1 said. On a large frame, high flow machine with extra cooling they're a beast. For everything else a dedicated grinder is real tough to beat. I started with a lo flow grinder, ran that for a bit then started renting a gas stump grinder, after a year I said screw it and bought a diesel unit with a remote control and never looked back. Smaller foot print, better visibility, cheaper to run, and way more productive.