I have a 6 x 12 flat front, single axle Haulmark trailer that I bought used from another modeler several years ago. Works great and rides well but if I were going to buy a new trailer, I would buy one with a V front. I also pull much heavier boat and stock car trailers with my full size Chevy truck and at speed, my light weight airplane trailer pulls the hardest because of that flat front. Yes, you want torsion bar suspension and a front side door is a requirement ... at least for me. I think if my trailer had a V front, I could get by with a 6 x 10 but when I went to look at trading my trailer for a smaller one, I couldn't justify the cost difference when the only disadvantage of mine is the wind resistance.

There are many good brands out there (both regional and national) and most of the aluminum skin over wood and steel frame trailers are build in a similar manner. All aluminum trailers are a waste of money in my opinion because we're not hauling much weight. A heavier steel framed trailer probably rides better. Again, wind resistance is more of an issue than weight.

As for options, just go look and find something you like. I prefer rear doors that swing to the side, some prefer a single door that lowers to a ramp. Get the best latches they offer. Some trailers will have lots of diamond plate, some will be plain. Light colors are much cooler inside than dark ones. Oh yes, because of our low weight, I use good automotive radial tires to help improve the ride. Best part about my trailer is that full coverage insurance costs less than $20 / yr.

Let us know what you decide on.