They can’t make them 8 ft between axles because they’d be too wide for interstate use which is 102 inches or 8 ft 6 inches. 8 ft trailers go over the tires and are readily available. Sure, you lose the space where the tires would be. Maybe that’s what you are calling wide body, but a true wide body is 8 ft 6 in.
My custom utility trailer has a 5 ft floor x 10 ft long and is just under 7 ft with wheels. I wanted it to be able to fit inside a standard garage door. It has a 3500 lb axle. Without TC it isn’t bad for width as long as I have the sides on. Perfect width for pulling behind my Explorer. I’d want it wider if I was pulling behind the TC regularly.
I did pull my wife’s uncle trailer to Yellowstone and back to the Seattle area behind the TC. It’s a 7 ft wide model and was almost impossible to see even with wide mirrors. In that case, the wheels don’t extend past the body. He bought a short narrow one because he tows it behind his Toyota Tacoma.
7ft wide plus wheels would probably be pretty good.
