I bought my 2019 new body style 4WD Crew Cab Bighorn pretty well loaded out (towing package, north package, level 2 package) with the Hemi for $37k + tax/tag, and I got another rebate on top of that so it was really $36750. If you plan on keeping this truck for a long time, you would be foolish (in my opinion) to save a couple of thousand bucks because you don't want a payment and get a truck that doesn't have the options you want. Of course that can be a slippery slope where you pile on options and end up 15k beyond what you wanted to spend, but saving $1k by buying the V6 is penny wise/pound foolish if you ask me. For one, the truck will be worth less if you wanted to sell.
Let's say you ended up paying $5k beyond your 'budget' and you plan on keeping the truck for 10 years. That's $500 per year. If you've saved up enough cash to buy this truck outright, how long would it take you to save a couple thousand more?
Two things you should really think hard about what you really want and then buy them when you're getting the thing: cars and houses. Because it's expensive to change your mind, whether that means adding on options or adding a wing onto a house. There's a thread here somewhere a guy bought a truck and now wants an E-locker. Well, it was a $500 option when he bought the truck, but trying to retrofit it will cost way more than that.
So if you want a Bighorn with a Hemi, you should go buy a Bighorn with a Hemi. Leave off the 12" display, the E-torque, the Panorama sunroof and the bling wheels and you should be able to buy it in the upper middle 30's like I did.