Yep, the Mad Force looks like a big truck because it sits pretty high and the chassis overhang and factory wheelie bar make it seem longer, but it's footprint is close to that of a Savage. All of those bodies would look good on it.

How much did you stretch the wheelbase? Use that to determine whether you use the Losi or Proline VW body. The Proline would probably look better on a stock Mad Force, but if you stretched the wheelbase an inch or more I would go with the Losi version.