Welcome!! You will find this website very handy for all types of questions! I agree with EddieWalker a wide wheel base would be safer. Also if it were me I would look for a hydro instead of a gear tractor. I think I would feel more comfortable with a hydro on a hill. I own a gear tractor now and when I operate the clutch on an incline it makes me nervous.
Buy used! I did twice! Got two great tractors that I still own today!
But do your homework, and don't be a compulsive buyer, there are a lot good deals out there. Check tractorhouse.com