Hi FREPRO,
There's a placard on the front of the trailer, off-door-side that lists the GVWR of the trailer, along with the size of the original tires. It would help to provide that information. Also, if you look at the inside surface of the wheels, there should be a number stamped into the metal. Probably either 80 psi or 3250 lbs. Possibly 110 psi or 3750 lbs. That would also help you get a useful recommendation.