Hi tigger, welcome to the forum
The fact that you'll be running on a treadmill will reduce the shock compared to running outside a fair bit - it's a much more forgiving surface. Most trainers will be able to offer a level of cushioning and stability, but there's not one specific shoe/trainer that can really be recommended to you without being able to take a proper look at your running style.
If you can get yourself to a running specialist store, they'll be able to suggest suitable trainers for you (hopefully with the aid of 'gait analysis') and you should soon be back on track with your running
