The DC motor proposal is by far the best for this application.  For
less than $300 you should be able to find a suitable motor-controller
combination from WW Grainger, an industrial supplier.  You may have to
find someone who can buy from them, but they do have these available.

Do a search on their web site and look for "DC motor and controller
combinations".  I would think that a 1/8-horsepower or less motor
should do fine driving that roll frame.

Rich Sitler