Appropriate tow vehile

What are you trying to tow, like a 27 foot bunkhouse or a 20 foot singles trailer? How many people are going to be traveling with you in the tow vehicle, and will the tow vehicle have to double as a daily driver?

This is a math problem. You need to know a few things. the weight of the TT loaded for travel (water, food, gear, etc). You need to know the GCWR (gross combined weight rating) of the tow vehicle and you need to know the tow vehicle's weight - with people, fuel gear. The difference of the GCWR and the weight of your tow vehicle will tell you your capacity. If that is more than the weight of the loaded travel trailer, you are good to go. You hav eto be careful with advertised towing capacity on trucks. They do not account for fuel, gear, people etc. 4 people and gear can easily chew up 1,000 lbs. Then there is the trim level. Everything that is added to the truck adds weight and thus decreases your capacity. Then there is hitch and tow ratings for the tow vehicle itself. It is always the lesser of these factors. You are talking about a 30 foot travel trailer weighing almost 8,500 lbs dry and empty. That's a lot of trailer. I would give the salesperson an earful. Unsafe with the Cherokee is an understatement. I am not sure a 1500 series truck has enough capacity. But you can look those figures up on line. You probably need a truck with at least 10k capacity. Most 150/1500 series hover around 6-10k depending on how equipped. You cannot have too much truck. It's easy to have too little as you are finding out. 

I pulled up the specs, 8279lb dry with 1521 payload, so a GVWR of 9800lb. GVWR is a good preliminary estimate of what the trailer will weigh going down the road.

Your V6 Jeep was never even close to being within ratings. The V6 has a max tow rating of 6200lb and a payload of 1260lb. Your trailer is 50% over the tow rating and you should be looking at 1200-1500lb hitch weight (which counts against payload and you want in the 12-15% range for good towing), so you are at or over payload before putting a single person in the Jeep or anything else for that matter. 

1/2 ton trucks get tricky. There are rare models with up to 2500lb of payload that you might get to work but the vast majority have payloads in the 1000-1600lb range. They won't be significantly better than the jeep. If you are set on a half ton truck, really watch the ratings and as way2roll said, lots of other things count against payload.

Honestly, I would jump straight to 3/4 ton trucks. At the low end, they have payloads in the 2800-3000lb range, so you can handle the hitch weight and still take people and gear in the truck. While diesel is nice, it's overkill. I would look for the larger gas engine (6.0-7.5l depending on brand). That will handle a 10k trailer comfortably.