All those numbers apply to level ground, esp towing capacity. Everything changes when you are going up and down hills and over mountain passes. What size engine is your truck and gas or diesel?
2 good rules are to never go over 70-75% of your towing cap and be well aware of the weight ratio between your towing vehicle and the trailer. You do not want to be pushed down a hill and cause a jackknife which could be deadly.
To give you an idea what you can get that is under 5,000 lbs, we have a 21 ft Rockwood Mini Lite that has a space saving queen sized Murphy bed (it’s the way to go) and it is 4841 lbs and 641 lbs hitch weight. With an anti-sway hitch it moves weight forward and back and reduces hitch weight. We pull it with a Ram 1500 5.7L engine, 10,000 lb towing cap and it bogs down going over passes out here in ID. We are upgrading to a new 2500 6.4L 15,000 lb towing cap next week.
So to move up to a quality 25’ range adding bunk beds and stay under 5,000 lbs will be a challenge. If your kids are little they can sleep on the converted dinette bed.
So even though you may see people towing 25’ trailers with standard 1/2 ton pickups or large SUVs, many of them have dangerous weight ratios.
Good luck!