Originally Posted by ALC-GregH
You would be better off with a garden type tractor. Kubota makes a 4wd tractor. They aren't cheap though. 15 degrees is a very steep hill. You'll have a hard time finding something that will work for what you're trying to do. Is the place yours or a customer? Also, what are you trying to accomplish? Are you bagging grass or is this for leaf clean up?
The bad news is this yard is mine nice fescue on a hill (what could be worse), I do not bag the grass only do the leaves. I hate tractors but I may have considered them.