As stated above you need you think about weights and usage of the tt. some rv resorts limit age of tt, some national parks dont fit longer tt, you have to realize the longer you go, you trade off some nice sites. If you boondock you want larger tanks if you will always have full hookup then tank size doesnt matter, Also I would not tow a 26 ft TT with a taco. It will not be a comfortable feeling.
now lets discuss what you can tow. Instead of telling you what you can tow, I'm gonna show you how to correctly figure this out. This way a salesman won't sell you something you really can't tow.
You need to know more about your trucks capabilities than just my truck can tow x lbs. (I learned this the hard way). Most TV are limited by their payload. To find out your TVs true towing capacities then you need to go weigh it. Load the tv up with all occupants, pets, and cargo that will be in it when towing plus a full tank of fuel and then go weigh it at a local scale (
www.catscale.com). Weigh each axle on a separate scale pad so it will give you a breakdown of front and rear axle weights individually and a total weight. Take the total weight and subtract it from your Trucks gvwr to get your available payload. Take the scaled Truck weight and subtract it from your Truck gcwr to get your adjusted towng capacity.
Now understand you will never tow an unloaded or dry trailer. Those numbers are somewhat irrelevant. You can either add the amount of weight of cargo you will tow to the dry weight (this is heavier than you think as most add 1000-2000 lb of gear) or simply use the tt gvwr to do your calculations. Being that this is your first tt, using the tt gvwr is the safer route for you. Next understand that the tt loaded tongue weight needs to be subtracted from your available payload. The loaded tongue weight is typically 13-15% of the loaded tt weight. For your purposes go wiith 13-15% of the tt gvwr. Remember you will need a good wdh. Sway control can be determined by the size of the trailer. For less than 26' you can typically get a friction sway bar and be ok. For over 26' you want a wdh with integrated sway control like the Reese dual cam or equal-I-zer. You can use integrated sway control for a smaller trailer and many will argue about which is better to use at that size (they each have pros and cons). Hope this helps you understand why we say no way to 6500 lb towing capacity.