You guys must run them a lot harder than I do, I have five SCX24's and not had any motor problems yet. I think I've had my deadbolt about a year and a half.
Make sure whatever you get will fit the stock motor mount, otherwise make sure you get a combo that comes with a motor mount. If your looking for the cheapest option the stock motor is under $8.00 at Horizon Hobby. Going to be hard to beat that.