Please don't listen to the dealer (either GMC dealer or TT dealer) on what your Suburban can tow. Do the math yourself.
If you don't have access to a scale, or don't want to do all the weighing prior to final decision, at least do this.
1) Look on drivers door jamb for the yellow sticker. This will tell you what your max payload for the Suburban is. Lets say, for sake of argument, it is 2000lbs
2) Estimate the weight of all occupants, and potentially an estimate of what you might carry in the Suburban with the occupants. Subtract that from the payload number in item 1.
3) Look at the trailer max GVWR. This info is on the sticker on the left side of the trailer. If it is not spelled out specifically, it will have the unloaded vehicle weight (UVW) and the max cargo. Add these two numbers together. Lets say its 8800lbs as shown by 2012Coleman.
4) Take, for planning purposes, 15 percent of 8800. Your tongue weight should be between 10 and 15 percent of the trailer weight. Worse case would be 15 percent, typically try to hit 13. So, worse case, your tongue weight would be 1320
5) Your cargo number, on the yellow sticker in item 1, should exceed the sum of item 4 (tongue weight) and item 2 (passenger weight and whatever you carry in the Suburban), AND the weight of the weight distribution hitch (estimate 100 lbs). If the sum of these three figures exceed the value on the yellow sticker, you have too much trailer for the vehicle.
Now, one will/could argue that you won't load the trailer to max, and as such, save some weight. BUT, until you KNOW what you put in the trailer, you HAVE to estimate. So, estimate high to give yourself some cushion.
Thank you both for your service. As a retired AF guy myself, I know the sacrifices you BOTH have made.
Mike