[aerotruk63]

When placing your load in the trailer, the trailer manufacturers require 60% of the load over the front section of the center of the axle. You also have to keep in mind the tongue load, generally in the 200lb. range for pickup range. You'll see these types of specs stamped into the step bumpers or on the receiver units bolted to the frame. I don't think you'd be loading your new trailer to max capacity. More so than axle capacities, tire specs are important here. Were not allowed to use passenger type tires on a trailer and the tire stores are not allowed to sell or install a passenger type tire onto a rim KNOWN to be installed on a trailer. Trailer tires have different ply styles to allow the tread to twist. There are trailer tire ratings with letters that will indicate their capacity. Trailer tires are available in Bias Ply and Radials. Generally a trailer radial will start with an ST then the tire size.
I've found that a Bias Ply tire will hold more load and remain stable, but they bounce along the road when unloaded. Radials run smooth behind the tow vehicle. Of course you have to get stopped by an officer for these rules to apply and that will happen if you ever have an accident involving your trailer. There is a Grandfather clause to the rules here if the trailer was built years ago before the new rules came into play. However there's no Grandfather clause for commercial trailers.
Not trying to hijack your thread, perhaps you might want to ask your local DOT before you go to far.
You are allowed to build your own trailer here with a 1000lb capacity, but it cannot be used commercially. Tail lights, clearance lights and reflectors may be required when you go for licensing unless you have a trailer plate already. Trailer registration here have the color and number of axles and tire specs indicated. we have 6 single axles trailers in the family and two dual axle trailers to which we swap plates between. Dad has been stopped once in all his life for the trailer and they never enforced anything.