I bought a 24 ft boat in last year and the mob in Florida i bought it off had an Ezyloader ally I beam trailer there all ready to go with Au.spec Led lights, 4 wheel electric over hydraulic disk brakes, 2.45 wide. It was pretty much ADR compliant except for the AU. stamped hitch and rated chain.They export alot of boats to Australia and had one in stock ready for the occasion.It cost $4700AUD.Brand new.I rung Ezy loader direct and they said they could do it with the right hitch and chains if i could buy them here and ship it to them.I couldn't be assed.The boat and trailer came over and it left the dock on a tilt tray and went to Opal trailers at cleveland to get the hitch and chains done.$150.Opal have their own tilt tray so it was pretty easy for them to pick it up and take it back to get the stuff done.When i was looking for a boat i got a quote from Dunbier to build the exact same trailer and they quoted me $12,000 and after the guys down at Opal saw it they also said it would be about that much if they made it.Its a work of art.The only problem i had with the tyres was when i was trying to get a spare no one here could get that "special"USA size, so to save the mucking around i got the trailer re-shoed and sold the other tyres.In the end the change over was bugger all.So with the trailer all good i went down to QLD transport and and it was all good.Just like that.(make sure you have your authority to import a trailer).Who ever recommended Don Bellshaw i ditto that.He's a great fella and if its got to do with U.S boat trailers he's got/can get it.On the 2 inch ball idea i'm not really sure if thats the answer and as for the wiring of the trailer and the plug mine came with a 12 pin plug and when i got my in cab controller done by Wynnum Towbars, Leo actually drove down to Opal Trailers at Cleveland, worked out which plug was which and did my car the same.For me its a no brainer....$12,000 vs about $5,000.