First, the hitch. All OE receivers on pickups until some recent HD trucks are a 2" receiver. You can put any size ball hitch on them.
If you're looking at 15-20 yr old $5k pickups, honestly the condition and miles are worth more than the Brand. All 3 mfg had solid drivetrains except Dodge IMO was the weakest trans. I had several of them. Never lost one but never liked them. I still would buy a 2nd gen Dodge in a heartbeat.
Cost diff for 1/2 ton vs 3/4 or 1 ton will be negligible. It's all about miles and condition unless you're talking Cummins Dodges. They still command a premium for obvious reasons.
In that age range I'd be looking for 3/4 ton trucks. Mainly for bigger brakes and suspension.
That said I put a******ton of miles and a lot of towing on a few 90s model GM 1500s and they handled it well.
If I had $5k to spend on the best truck I could find I would be looking for a 1990-1998 GM 2500 with a 350 and NV4500 5 speed. That is still one of the most bulletproof combos out there in my experience.
And if you don't need 4wd that helps your situation a lot.
Edit, sorry, I didn't realize c r a p was a bad word!