There are only 3.45 for non Rubicon and they come with 4.10 only. 3.73 is for Diesel only and that's new for 2020.
JL has aluminum outer knuckles, axle vacuum disconnect like a YJ/Ram has. Better MPG. Stronger ring/pinions. The JL has 8 speed auto vs JK 4 or 5 speed autos. The JL has available heated steering wheel.
I am huge fan of the 4cyl turbo Rubicon. Huge power from dead stop and highway passing. It takes some getting used to. Plenty of gearing for 35/37" tires.
Must have options IMO:
Trailer Tow HD electical, gets you the AUX switch so no need for cluster wiring when adding lights plus the dash is lacking space
Cold Weather
Technology group, gets you the 7" radio but also the nicer dash and cluster, the 5" radio only has a volume knob on the radio itself, so dumb