That 4.0 is an insanely bullet proof engine and even irregular oil changes with the cheapest oil money could buy (that's API rated) will see that engine well past the life expectancy of your frame.
Sadly, your frame is notorious to rust and rot. Being in the NY, your frame integrity is what is going to be the determining factor on your Jeep's lifespan.
If your frame is solid and you work diligently to keep it that way, I would say rock whatever oil you like that meets the spec!
That being said, I personally like synthetics and run Red Line and M1.