Another option would be to have a helicoil installed which inserts a pre-threaded coil into the stripped hole to return the hole back to its original size.
The only thing here is will the section of metal be thick enough to make use of a heal-a-coil.
http://www.emhart.com/products/helicoil.asp
Here's another type of the commercially available units called a "Time - Sert"
http://www.timesert.com/html/mtrcsert.html
This can be done for you at any competent shop. But like I said, it really depends upon the thickness of the section of metal you intend to fit one of these coils into. If its thin, I would just opt to have the stripped hole opened up and re-tapped to go up to a larger size bolt.
Ken