I'm in the market right now. It's nuts out there. I just had a long conversation with a rep for a couple trailer manufacturers and he is having serious inventory issues. Every week, the invoice price for trailers is going up by $100-200. He said that if I wanted to order a new normal-production trailer, I was waiting 18 weeks. If I wanted an option like tie downs or a different door, 23 weeks minimum.
All of this is driving the price up hardcore. A trailer model I looked at one year ago (an 8.5 x 24 enclosed) that was $8495 is currently selling for $10,995. Non-enclosed is not quite as bad, but still nuts.
I say that mostly to let you know, if you find the trailer you want, buy it. Dealer lots have next to zero used inventory because people are paying crazy prices on FB so no one is trading them in. This is translating to the used market as people are paying more and more used.
Having said that, you should be able to find a 16' tandem axle 7000-lb flatbed pretty easily. Concerning the fold-down expanded steel ramp gate, that is wonderful for lawn tractors and light things, but something like a compact utility tractor will destroy it the first time you use it. They're not a heavy duty option. Even if you get the heavy duty angle-steel ramps that fold up, I still don't like them. Consider the picture below:
A fold-up ramp would have meant that I couldn't have trailered this vehicle. No way to fold up the ramp. Some of them have braces with multiple holes that allow you to stow the ramps in an angled position, but I don't think I could have done it with any kind of fixed ramp. The ramps on this trailer stow in a pocket under the bed. It's a tiny bit more headache, but it makes a far more useful trailer in my opinion.
This trailer is also lacking one other thing that I would love to have - tail jacks. When you're loading a heavy thing (like this van) you're going to want something under the tail of the trailer. I just carry some 2x and 4x lumber to space it, but it sure would be nice to have a swing-down jack on each side like the ones on my boat trailer. If you don't support it while loading heavier cargo, you risk damaging the tires, the trailer frame, or popping the trailer off the ball. I only suggest that because you mentioned heavier cargo in the future.
By the way... the trailer above is a 7 x 16 deck, total of 8.5' wide, 7000 gvw. It has stake pockets if you want to make some sides, and many manufacturers offer pre-fab sides if you wanted to go that route. Another nice feature this trailer has that the fenders are easily removable. You mentioned forklifting pallets on to it. The fenders prevent that unless you're loading to the extreme front or rear. On this one, you just pop the fender off and slide one of the forks between the tires to load in the center.
It's all preference. I like spring axles, some like torsion. I like wooden beds, some like steel.