Hah, yeah the chain thing. I'll just tell you my setup as requested and you can argue everything except grade of chain.
I tow with a 98 chevy half ton truck. 4x4, 350 engine, auto tranny, with gauges to monitor transmission temperature and manifold vacuum. I use stock size LT tires in load range C. It has engine oil and trans oil coolers with the tow package. 143,000 miles. I set this truck up for RV hauling and it works very well, not winning races, but very stable and effective. I am within all axle ratings and tire ratings. The tow rating is 6500 (oddly, the tow rating for the 3/4 ton version is less) which I use every bit of. I get 11 mpg hauling the tractor 80+ miles round trip, I have broken 20 mpg several times on highway cruises when not towing.
I then go through the stock GM receiver hitch to a Robin WD hitch system rated at 10,000 lbs, even the 2-5/16" ball is rated for 10,000, I use 1000 lb spring bars.
The trailer is a PJ Trailer. It is 18' including the 2' dovetail. The channel in that photo is all 6" tall. Even the wrap around tongue. The trailer weighs 2500#s and has two 8-lug, braked, 5200# capacity dexter axles with e-rated tires and a GVWR of 10,000. (It might be 10,400). The lights are all recessed, non-LED, standard trucker style, and rubber mounted, the ramps are 5' long and slide in sideways under the dovetail. It uses treated 2x8 decking that is bolted down and the planks are individually removeable and replaceable.
So I run the tractor up therein 4wd, about 4000-4500 lbs. I locate it so that I have just the right amount of tongue weight, drop the implements, and then set the parking brake. I use the stake pockets and the typical double hooked chains. Mine are 3/8" binder chain of phenomenal working load limit. I use two short loops around the stake pocket and the tractor attachment point. I don't use a single attachement point on the tractor such as a big shackle since if that shackle (clevis?) came undone then both chains would be defeated. The independent chain off allows for any one chain to fail and the rig stays put. So between the short loops is some 16' of chain. That's too much so I hook in the ratchet binders of phenomenal working load limit and bind down the tractor, I wrap the extra chain around the bider three times so it doesn't fall off the deck and drag. The only trouble with the ratchet style of binder that I have found is that water can get into the ratchet mechanism and freeze it solid.
I leave the ROPS up and just tow along at 60-65. No sway or porpoising. The trailer has extra unused capacity. That was intentional since I like to be within the working load limits and not on the ragged edge. The truck is at the ragged edge and if it ever proves insufficient or independable then it will be replaced with a 3/4 or one ton. So far so good.