From memory, they are mounted on a Suzuki chassis, but I forget which model. I believe that the chassis are unmodified in length, & in fact run the full stock Suzuki drivetrain.
The other side-shot of the red one shows that the body is mounted high, but the chassis is not all that high, so the high stepin' look is more of an illusion than the result of a seriously jacked up suspension, which I think is also stock.