My boat is 17'7" Avenger.It came from the previous owner with a single axle RoadRunner trailer.It seems to be a well built unit,but I want a tandem axle(rough Louisiana roads).Anyone recommend any particular brand? I've been searching the web but haven't found but a few trailer sites.I'd like to get a RoadRunner tandem....any know if they have a site? I haven't been able to find it.