[Notanlines]

Nate, you're heading the exact way most newbies go with the BS tow capacity listed. That isn't the most important, even close to most important. He was directing you to look into the 'cargo capacity' of your truck. There will be cargo, hitches, four or more passengers, suitcases, tools, etc, etc, etc in your 20 year old truck. Then you will add the pin weight of the RV. Generally use 20% of the gross weight of the RV. Do NOT believe the RV salesman, and sure as hell don't believe the statistics published by the truck manufacturer.
Fill your truck with wife, kids, and a few things you think you might bring on a typical trip. Drive to your friendly CAT scale and weigh the front (steer) and rear (drive) axles. Any large truck stop has the scales for about $11.00. Look on the sticker on the driver door pillar for the GVW of YOUR particular truck and subtract what your truck weighs. What's left is the weight you have t play with. Nope, don't hand us any happy BS about air bags and extra springs and big tires and blah, blah, bah. That won't fly.
Then get back to us and we'll go from there. Kudo's to you for wanting to be debt-free. A noble thought for sure! And, by the way, the RV you're looking at has similar models that just sold for 6K and 8K.
Jim