I did the swap myself using a Motech kit. L86/8L90/Atlas. Using a L83 will reduce some costs in the cooling department, but I think that's really minimal.
Your rubicon transfer case is not compatible, and I don't think you can control the GM transfer case without a BCM, but I'm not sure on that. It's a long transfer case. I would suggest to get a normal JK Case if doing this on a budget.
Read the Motech documents a few times, lots of good info there. Downloads
The kit is pricey, but overall it is well thought out. You will need to send them your jeep's engine harness to be reworked as well as the L86's harness. Engine mounts are bolt in and have some adjustment to position the engine where it doesn't hit anything. You will most likely need to lift the body up some. I welded together some washers and got longer bolts, doesn't need but about 5/8".
You will need HP tuners to get it working right and not have the dash lit up. Being a 2018 engine, it's more costly to unlock than the 2016 and down. Go to the HP tuners website for more info on that. The transmission computer is also going to be locked, but you shouldn't need to get into that.
Transmission takes a special oil, it's pricey and may not be available everywhere.
There are a couple guys on this forum that have done the swap, read up. One said he is using the stock JK radiator with his L83. The cooling fan is a different animal but I'm sure there are a few ways of attacking that now. Most expensive way is using a Camaro SS fan controlled by the GM computer. That'll also cool the best.
Even tightest budget, making sacrifices along the way, I bet you're still over 10k before you're done.
But it is worth it!