You would need a suitably sized engine. A new one would be good but secondhand would do. This could be acquired from an authorised dealer . This could be mounted onto a suitably made frame and would need to have rubber engine mountings for the vibration.
A water pump would be required and would be run at the front of the engine using a suitable pulley. The blower, which i think might be difficult to find, would be run from the back of the engine. Find a suitable waste tank and piping, a fuel tank etc and you would be nearly there.
I think anyone who makes them, would probably need certification to prove their safety. Somewhere on here there is already a thread about it and pictures of a self built one.
Dave