If you have a rhino or two lying around doing nothing, they can be looted. If not, go to a dollar bill store, and see what else might be waiting for your lootin' pleasure. Shermans are often available, as are other toy soldier tanks/vehicles.
If you cant run the list without deffkoptas recommend running squads of 3 and outflank with them. Its randam when and where they can come in but it has the possibilty of throwing a nifty midgame distraction into the opponents ranks.