There are other models of the SC, but no bigger. The Mule 4010 is a little bigger, the Mule Pro MX a little bigger yet. Finally the Mule Pro F or D series is the biggest. F series are FX, FXR, & FXT. The D series are diesel powered, DX & DXT. You might want to try an MX, or FX for size.
Kawasaki does not certify for on road use. So the Feds will not get involved. I doubt your state or insurance company will certify for street use.
My county allows ATVs and UTVs to drive on the road, but with severe restrictions, much like areas that allow golf carts on the roads. We are limited to 25mph, must have lights on, not operate after dark, AND are considered AT FAULT if involved in an accident.
I would look at trading your SC for a larger Mule.
I had a 1996 2510, back when the only choices were golf carts and the 6 wheeled JD Gator. I bought an F series Mule, much more machine.