Tuners
 

Is there anyone with advice on the best tuner for a JK and if they are worth the money?

I have a Bully Dog 40417. Personally, I'd steer away from Bully Dog. Sometimes it's just a pain to deal with, and I've spent time on the phone with their support team several times along the way. I've used a Superchips Flashcal in a pinch recently after regearing (and while having issues with my BD), and that interface was really nice. Very straightforward. Their Flashpaq is essentially the same unit with added functionality.

Are they worth it? Meh. Adjust tire size, gears if necessary, mess with a few more settings. You're not going to notice any power difference or anything. When I bought my Bully Dog, I tried out all the various tunes. I just leave mine on the regular tune now. I don't even change for the trail.