Assuming...
Kids=300
Wife=150
You= should be included in payload already
Dogs=140
Cap for the dogs= 200
12percent of 7500lb trailer (conservative)=900
Hitch= 100
Total payload= 1790 lbs
Ram 1500 with V8, crew, 4x4 payload= 1400 lbs: http://www.ramtrucks.com/en/towing_guide/?sid=1037056&KWNM=ram+1500&KWID=43700008362948452&TR=1&channel=paidsearch
Even if your WD hitch pulls 200 lbs off your hitch, you are still way over on payload.
Truck weighs almost 5200. GVWR is 6800= 1600lb Cargo capacity. You will be over payload, and GVWR and I imagine at 95 percent of axle ratings.
You have better payload with your v6 because the engine is lighter. Do it right and go HD or lower your cargo capacity (take 2 cars). If you remove the dogs, wife, one kid, cap, you will be well within range, even with your current V6 (just slow going).