If you do some searching of the archives you’ll find lots of “best truck for towing” threads.
If you boil them down you’ll find some common thoughts:
For most folks, bigger is better. There is a minority view that “less is more.”
Dually and 4wd tend to be preferred over rear 2wd. Again, there is minority view that these are “nice to haves” but not “need to haves.”
Diesel is widely preferred to gas for 3/4 and one ton trucks. There is a small minority view that disagrees.
Long bed vs. short bed is a lively topic. The long bed is more utilitarian for hauling and towing gooseneck trailers (shortbed trucks can have problems with cab being struck by the nose of the trailer in tight maneuvering). Shortbeds are lighter, get slightly better mileage as a result, and are easier to park.
DRW vs. SRW also can get lively. The DRW gives a bit more stability but negatively impacts mileage and parking ease. It’s also more expensive in terms of tire costs.
Regarding cab size a very large majority seems to prefer the extended cab or crew cab.
As you read you’ll find more but this will get you started.
Remember, as you make your selection, the First Rule of Towing Anything:
Starting Is Optional, Stopping Is Not.
Ignore the “towing capacity” claims of all manufacturers. Find (in the owner’s manual or on the driver’s door frame) the GCVWR (gross combined vehicle weight rating) for the truck. This is the maximum legal weight for the total of truck and trailer. Then get the curb weight of the truck and empty weight of the trailer. Calculate as follows:
GCVWR - (Truck Curb Weight + Trailer Empty Weight) = Legal Payload of Trailer
Remember to include in curb weight the numbers for passengers, fuel, stuff, etc.
I’m generally of the “bigger is better” camp as I view what I have to pay for excess towing capacity to be cheap insurance for the health, safety, and welfare of me and my horses. I’m ready, willing, and able to buy the extra fuel, maintenance, insurance, etc. that my view requires. As with all things, YMMV (your mileage may vary).
Good luck in your search.
Subtract the sum of those from the GCVWR. That will give you how much load you can legally, and safely, put into your trailer.