As others have mentioned, use at least a 5200# axles with brakes on both axles. Over the years I've seen enclosed trailers with 3500# axles that have the tires tilted in at the top. It doesn't cost much more to upgrade to the right axle. IMHO on any 24' trailer it should be mandatory to run at least a 5200# axle. My 18' open goose neck car hauler has 5200# axles under it.

Buy good tires. I tow with a open trailer and last summer installed 15" Goodyear Endurance, load range E radials. It tows nice and smooth, money well spent.