Lots of good advice. As far as size get the biggest tractor that you can afford and have room to maneuver. If you look at tractors side by side there isnt that much difference bwtween the mid size Ls and the large Ls, but you get bigger tires, more ground clearance and more lift capacity front and back.
If you are moving snow have you considered a cab? I went from a small, open station B to the cabbed grand L and would never go back to an open station machine. Just have to be careful in the woods. Other options I have found helpful are the Rimguard loaded rear tires, SSQA, front hydraulics ( I have Kubota's), rear remotes (I have used both sets on mine). The rear remotes can be ordered with a float position which is useful in some application. If you get the cab, rear wipers, rear defogger and work lights have been useful.
The grand Ls are very easy to run. My wife is 5'2" and has no problem running our cabbed machine. She was smiling this summer siting in the cab with the AC and radio on.