So I know you get what you pay for, but unfortunately I don't have the budget for a great treadmill. I really just want to do couch to 5k and get myself to a point where I can run that far outside. What should I look our for in terms of motor size and speeds? I'm a bit overweight but not above normal size limits. Essentially I just want to get myself running 5k (very slowly) and would prefer for various reasons to do that at home.