This isn't a real practical application for a compact tractor imo. I would consider a wheel loader or large forklift for this work. I would consider a one ton single wheel truck with a weighted bed and large motor and 4.00 + rear differential for towing.
If you still want a tractor for this type work consider an economy type 6140 Deere. This is a case for a high hp version for what ever frame size you settle on.
It takes lots of hp to pull a load up a long grade at a fast speed. This isn't what farm tractors are designed for, but some of the newer pickups and chassis cab trucks are perfect for this task.