If you want to have a clean exhaust setup, could have a muffler shop custom build you one - whenever i get around to building my rat rod wheelhorse ill take it to one and see what theyll charge.
On mine i want the pipes to come out, sort of bend around the footrests ( the motor should have a lil back pressure), run down the outside of the footrests and exit at the rear of the footrests - sorta like sidepipes on a car.