Shit, i haven't been to "my" jeep forums in so long, can't remember. Those 8.8's are pretty good axles and plenty beefy for 35's. Oh yeah, Jeeps-Offroad.com There's loads. Jeepsunilimited.com, Pirate4x4.com, jeepin.com. I tend to like the linked one best for just asking questions and talkin to others.
I'd say go for the header, sounds like you can benefit from the added flow. I have a '90 2.5. Yep, there is a downside to my jeep, but I actually wanted the I4 as not to overpower my drivetrain. In my jeep, I don't believe more power is better. I run 4.88s and have plenty of low grunt, more than I really need. However, I'd like some intake mods, but the 4.0 TBI will only fit 91 and up, my 90 has a different bolt setup. So, I'm furked!!
Like you, my Jeep has kinda been on the backburner. I still use it a lot, but I don't drag it to the trails like I used to, seem to be draggin the banshee more often. One thing about it though, you can hop in it and get looks from everyone in town. Jeeps are definitely head turners.