I don't have a good answer as the load carrying capacity will depend on the size of the axles, the type of wheels and the speed you will be moving the load at. My trailer has 1 7/16" axles and 16" pressed steel wheels I have loaded it with close to 2000 lbs and it will probably carry more. Nolan industries makes some speeder trailers you might start looking there:-
[
www.nolancompany.com]
Rasputin