I rebuild late model Rams I buy from the insurance auctions. It's all I have done for the last 8 years so I'm pretty much know them inside and out. First off DON'T buy an Ecodiesel. The Italian engine is junk. They are extremely prone to engine fires. A 5.7 Hemi 1500 is a nice ride and can easily pull a small trailer but with such a cushy rear coil suspension it is not designed for a lot of tongue weight. If you are towing a 24ft enclosed trailer I would definitely go with a 2500 at least. You can get a 6.4 hemi for less than the diesel but they just don't quite have enough torque at freeway speed (70MPH) to pull a 7K lb trailer. You will have it constantly down shifting from 6 -5th gear and watching your mpg drop to 9mpg. I would still recommend a Cummins if pulling a 24ft enclosed. It will drive and pull like it wasn't even there. No downshifting unless you were really going up a steep hill. I have owned at least 30 of the 2013 and newer Cummins Rams. Don't let the scare of high repair bills keep you away from one. You likely won't have any issue until it has a ton of miles (say 200k plus). The guys who do have Cummins engine issues are the guys who idle there truck for extended periods and the ones who pull the 40ft gooseneck fully loaded commercial trailers. Sure a diesel may cost 5K more to buy up front but it will also sell for 5k more when you sell it off, so it's only tying the $ up for a while.
I haven't been deleting the EGR system on my 13 and and newer Cummins for years now. Really not a good idea anymore since the EPA is really cracking down on that. My experience with highway MPG has been about 21MPG empty, 19mpg with an empty 2k trailer and 13.7 pulling 10K loaded trailer, so I've been happy enough in stock form. Heck, back years ago with 04-07 5.9 Cummins and no EGR they would only get 22mpg or so.
Like I said at the beginning I repair these and sell them. It's been a great niche for me. People get sticker shock over the price of a brand new one on the dealer lot for 70k. They just can't justify that kind of cash outlay for a truck they need occasionally. So when I offer a near new diesel one with low miles for 30-35k with a marked title it's much more palatable. For example I just sold a 2017 diesel with only 22k miles that was a theft recovery (they took the custom wheels) and no collision damage for only 30k. PM me if you want to see what I currently have available or coming up soon.