Best UK Treadmill? Or Elliptical Trainer?

I'm currently struggling with exercise due to peripheral aterial disease and I'm considering a treadmill (so I could at least have frequent, if short, walks). I really don't want to spend alot of money on this but would like my husband to be able to use it as well (he's 17st). I want a motorised one rather than manual. I can't seem to find a good review for any on amazon etc., unless I'm going to spend £500 (which I don't have). Can anyone recommend any treadmills?

Also, should I consider having an elliptical trainer rather than treadmill? It seems that you can get a decent one for less than a treadmill? Any suggestions here?