Not easy to find additional height and 10k#. Make sure you verify with the seller the door opening measurement and interior height before wasting your time driving. Insulated ceiling is nice in the summer and winter. Roof vents not required but nice to have. If you want a finished interior, expect to pay $5k+ for anything newer. Stick with the big names like Haulmark and Wells Cargo if you don't want cheap crap. Expect to replace tires if not new. RV style door latch is great to have. Most have torsion axles so the trailer needs to be level when loaded. I don't think that v-nose vs. flat nose makes that much difference behind a pickup like it might with a goose. Screw vs bonded exterior panels - screws do rust over time and both types wrinkle with hot/cold cycles. Arched vs flat roofs - as long as it is sealed both are fine.
Aluminum is nice, light, and fuel-friendlier but comes with premium price tag. Probably save nearly 2000# vs steel. Vintage, ATC, Featherlight.
Also 1000% sold on weight-distribution hitches too! Night and day difference.
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