steel is the easy choice....plus it can be fixed rather easy. IF were just towing a hot-rod or race car or something like that a 7k trailer would be fine. IF you are going to tow a 4wd trail truck around with a bunch of crap then you better figure out some estimate of the weight and add 500 to a 1000 lbs on that. I've towed with some 7k trailers and I've always been concerned about it, I used the newer uhaul car hauler trailer which is a very well built trailer a few times and the last time with the uhaul made up my mind....I got tired of watching the mirrors and wondering what the trailer was going to do and was nervous as to how it acted (no mater how I positioned my towed truck on it).. I bought the 10K metal deck trailer and over the last year made a few mods to it and I just load it, check the straps and lights and I'm off. No wondering, no shimmy, no handling issues at all. I want to have a non-stressful safe drive. The 10K trailers are not light, I would use a 3/4 ton truck for towing (or one ton) if thats the route you take. The PJ trailers are some of the best Ive seen (overall) but are $$ which may be just the price of fame...I would have bought a PJ but I did not have enough $$ at the time.
Features I like: Dual Axle, Dual brakes, metal deck, HD metal drings on the deck front and back or other locations for tie down, stake pockets on the edge and front, other tie down options at mid deck and or sides, LED lights, a good trailer harness protected from road rash, min 2 5/8 ball setup, a good lift jack that has an adjustable foot, marker lights on the fender so you can see the width of the trailer at night, HD trailer hitch (some are adjustable), powder coated, good safety chains and well designed attachmetn points for them on the trailer neck, a "dead-man" brake switch, good 7 pin trailer harness, stowable ramps or well designed loading ramps, a trailer that does not make a hell of a lot of noise empty, spare tire/wheel mount, place for a tool box to put your tie down straps so you can lock it. Fenders you can stand on , 15 inch tires or bigger on the trailer. 6 lug or better axles,
my trailer does not have it ( I do have two large drings in front and back) but I would like a dedicated dring iin the front and back (at the center front and center rear) for a dedicated safety chain connection, seperate from the strap connections...one day I may change that.