I've been in love with kayak fishing for several years. Got an idea to make a new build. Really light rig to pull behind my car or pickup for taking on long weekend fishing trips. The idea is for a rather light, small sleeper (no galley) with a steel rack on top to hold one of my fishing kayaks. 4x4x8ish. I will embed an AC and electric heater, windows and thinking of a wide single door. Tailer will contain the sleeper box, kayak and two external coolers (one for food/drinks, one for stinky fish)

I know the weight of the kayak and loaded coolers, but have still to figure total frame/sleeper weight. One prerequisite is using a four lug 13" wheel set that I can just pickup at any Walmart. I will carry a spare.
Plan is to have a ready-to-go rig for local overnights, fishing tourneys or long fishing weekends at the beach.
I want a light, good quality torsion axle. I built and used a Harbor Freight trailer as a fishing kayak hauler for a couple of years. The axle spindles wore out at about 2000 miles. Was not impressed.
I'd post a pic of a rough sketch idea, but I think the old image hosting site I used ten years ago is now defunct. Any new ones available these days?
Thanks.