Your GCWR info should be listed via a sticker on your Jeep. On my F150 it's on the drivers said door. GCWR is the total weight of your Jeep, your trailer, and ALL gear, cargo, tanks, fluids, dogs, cats, etc. It's not just the driver.
Given how close you are to capacity limits, I would not estimate anything. Find a local quarry or CAT scale and get your vehicle weighed properly.
As for the tongue weight, on my F150 I have two #'s. One TW is for a ball receiver on the bumper (500#), and the owner's manual prints a second number if you have a weight distribution hitch (WDH). In my case that is 900#. Tongue weight rating is just that...the weight of the tongue at the time you hook it up (with a fully loaded trailer, typically)
IMHO, WDH w/sway control are invaluable, particularly for a short wheelbase vehicle such as a Jeep with such a low TW rating.
I put a spreadsheet together that helps you figure out your weights, assuming you have access to a scale. I have a sand & gravel quarry down the road that's pretty convenient.
See here: https://www.dropbox.com/sh/6jzj9jm0572dcrv/jNKKP1P_4M/Vehicle%20Weight%20Calculator.xlsx
