I have been in the trailer industry for over 30 years on the supplier side as well as manufacturing and dealer development, and I Personally I would not get anything less than a 24' box with tandem 5k axles and brakes with each axle. Your tow vehicle dictates how much trailer you can pull and while many 1/2 ton trucks have plenty of towing power, they don't have the suspension or brakes necessary to keep everything in a straight line should driving or road conditions deteriorate. I would not recommend anything less that a 3/4 ton truck with a quality hitch and sway control. There are plenty of car haulers on the road with tandem 3,500 lb axles (7,000lb gvwr) but they are rolling on the ragged edge of design capacity. Tandem 5k's ensure that you aren't working your equipment to death while transporting your pride & joy. (There is also a little known option of tandem 5,200 lb axles for a minimal upcharge)
I would also recommend Dexter TorFlex, independent suspension torsion axle running gear over conventional leaf spring axles. They allow for a lower ride height which makes it easier to load and unload your vehicle as well as a smoother ride with minimized bouncing and a truer tow. Dexter is the industry leader and trailers with this suspension are widely used and not hard to find. (link below)
The reason for a minimum 24' box is simply space for your stuff. The number one complaint from customers over the years is that their trailer was too small and they wished that they would have bought the next size up. The escape door option is nice, but usually very pricey. For less money you can get a winch which negates the need for the door and also comes in handy when your ride won't move under it's own power.
Much like tow vehicles, the best trailer brand will always strike up a healthy debate. The only thing that I can tell you is that all the major manufacturers have been bought out or closed down completely since 2008. Prior to '08, the top three affordable mass producers were Pace American, Wells Cargo, and Haulmark, after '08 the water gets murky. Pre '08 trailers from these three, assuming that you're buying used, will offer good quality as long as they have been taken care of. (I would not recommend the Pace "Outback" model)
There are many higher end manufacturers such as Featherlight, Millennium, United, ATC, and others that are of excellent quality, but are priced accordingly.
At the risk of offending some members here, I will not list recommend brands to stay away form, however I would be happy to provide them via PM. I will recommend racejunk.com for used units. They usually have an excellent selection of fairly priced trailers.
Good luck with your search.
https://www.google.com/url?sa=t&rct...5pJQXGKWJmmRCNNNw&sig2=h2BUipNbjDQbV2ygcL1S2Q