stump jumper

I need a stump jumper and blades for a John Deere MX7. Where is the best place to buy?

While minding my own business, just driving along, mowing the grass, I heard what sounded like a branch being destroyed by the mower blades. But it kept going of for longer then it should, so I looked back and saw a round cap laying behind the gear box, and oil everywhere. I headed back in...