Pedal Go-kart Solidworks

Need a very rough 3D mock-up of a pedal powered go-kart including simple (bicycle) brakes, differential (see provided file), headlamp, and simple suspension such as leaf spring or double wishbone. Steering can be a simple wagon-style design with rotating steering column pulling wires attached to each front wheel (also in provided file). No gears needed at this stage. In order to accommodate different rider heights, the chair needs space to move forwards and backwards ~0.3 meters. Lastly, the kart needs some sort of thin plastic shell body that is open from the top (you are free to do whatever you think works best, simpler is better). Structural soundness of this shell is not important so long as there is space on the chassis for it to be fastened. Because this is in such an early stage, fasteners such as screws, precise contours of chair, or any other time consuming details need not be considered as long as the rough dimensions are correct. For example, the sliding chair mechanism can be represented by two solid rectangular rods under the chair, or the pedals can be represented by small flat rectangles. Lastly, please feel free to use pre-existing CAD files for any of the parts if this makes the task easier and faster. Just let me know so that I can purchase the part or have it re-engineered if we go to market. Except for the provided STEP files / driver dimensions, every other concept file is just for inspiration and need not be followed exactly.