Ok, now for my two cents, or at least my speculations on these subjects. Your TV may very well be able to tow the maximum weight specified in the owners manual. What you will notice is that there is no reference to trailer length in the Chevy/Jeep/Ford/Dodge manuals.
The longer a trailer is, the more leverage it has on the TV. This is the root cause of the "Tail wagging the Dog" syndrom, or trailer sway that we have all read about, and hopefully only a few of us have experienced (usually requires a change of underware at the minimum).
There are a many different ways to correct and or prevent this (with the emphasis on prevention.)
If you already have a TV, and trading up is not an issue, then use the wheelbase ratio calulations already mentioned on this page. If you don't have the TV yet, then pick your TT/TV on what you can afford, keeping those ratios in mind.
If you already have both the TV, and the TT, then there are two things you can do that will improve the way the vehicle handles while towing. First, get a high quality sway control and weight distributing hitch. Single Friction sway bars should not be used with a trailer over 24' in length. (recommendation from Husky) If you are using a friction bar, check your manufactures recommendations for setting up two friction bars, or change to a different sway set up.
Another way is too move the pivot point (ball and coupler) as close the rear axle of the TV as possible. Use a shorter hitch bar. This can also be done with a Pull Rite hitch (actually places the pivot point just aft of the axle), or the Hensley Arrow hitch, which, through linkages, causes the trailer to perform like the pivot point was at the rear axle. Both of these options come with a price though, $1700 and $2800 respectively.
Your could also go with a fifth wheel, which places the pivot point above the rear axle. Of course then you are looking at a full size pickup truck for your tow, in the 3/4 to 1 ton range.
So, to summerize, your Jeep may be able to tow 6500#, but if the length of the trailer is too long, it won't matter. The only way to know if your Jeep will tow the trailer in question is to give it a try, or speak to someone who has.
Well, I've said my piece. Good luck with your search.
Tim