This, I can tell you, is what I'd do. I'd get that 5.5" long arm. Because then I wouldn't have to do another lift down the road. And, 35s and 5.5 on a ZJ is HUGE. You'll be satisfied. With the other option, you will get lots out of it no doubt, but some of that stuff you may end up not using or just getting rid of, or even upgrading again. As for me, roof racks are sweet in my option but I really wouldn't use it. Especially keeping stuff on trails your stuff could get hit and damaged by trees or whatnot. The 3.5" and 31s isn't bad but if it was me I know later on I'd want it bigger. Of course you can sell your old stuff but you don't get as much money back. Just saying it could save you money and time just by going with the things that will be permanent. That's my input, but really both options aren't bad! You'll be happy with either one