I have the same truck but 2011. My trailers loaded weight is right around 6800 lbs. I would not want to tow anything heavier.
But, lets do the math. Your cargo capacity is 1638 lbs.
You are still using unloaded weights... Both for your current trailer, and the new one. You won't tow it empty. Lets assume, for sake of argument, you will have 1000 lbs of "stuff"... That's not unresonable. Puts your new loaded weight at 7935... lets call it 7900 for math purposes.
12% of 7900 is 948... Lets call it 950
Add 100 lbs for the WD hitch.
1638 cargo cap minus 1050 equals 588 lbs for you, wife, two kids, bikes, firewood, cooler etc. I think you will find out that you will exceed cargo capacity of the truck.
This all assumes you will only add 1000lbs of "stuff", in the trailer and that you will be right at 12% tongue weight. Likely you will be somewhere north of 12% so you lose more capacity.
Only you can make the best decision for you and your families safety. I won't pretend to make that decision for you. But, I will tell you, that, again, I would not like to tow anything heavier than I am right now, with my rig. My truck is the same as yours, and my trailer is lighter than your potential new rig. My loaded weight is less than your new trailer unloaded weight. I am actually contemplating a 3/4 ton just for more comfort and performance in towing.
Mike