Get a second hand compact tractor. Something in the range of 20-40hp. Sub-compacts are just high end riding lawn mowers, so I don't know if you'd be able to dig holes or scoop dirt like you want. I have a Kubota L series and it does plenty. Tears trees out of the ground, moves brush, digs holes. As much as people bitch about John Deere, they are still solid machines and you won't really get into that proprietary stuff until you hit the high end big tractor and implements. equipmenttrader.com might be your friend if you're still searching.