[CHDinCT]

Any of the smaller tractors with a front end loader (FEL) will work fine for moving dirt around especially with four wheel drive. Smaller tractors will just take smaller bites of soil. I assume you're talking about moving piles of dumped soil and the like. If you're looking to dig, a toothbar helps a lot when using a FEL, but a backhoe works a lot better.

Four wheel drive helps by increasing traction as you push into the pile and when transporting the load as the tractor's center of gravity will move further forward of the rear wheels thus reducing your traction at the rear wheels. Appropriate ballast on the three point hitch is really important in a small tractor that does not weigh as much as the full size utility tractors.