Welome to JF.
Headliner: There is a long old thread about it. I opted to take my fiberglass and cardboard headliner out, rip the material off of it, then I used a shop vac to scrape the foam backing from it. Got it super clean, then sprayed black bed liner on it...and reinstalled it. It's a very utilitarian look and everyone who's seen it loves it. ( so far, I havent posted pics). Others just take it out, remove the fabric and foam like I did, and recovered it with fabric. My thoughts are.....they'll be doing it again, sooner or later...but to each his own.
Re: Skyjacker: I live in the area (of that company). Not a very good reputation around Shreveport or Monroe, LA. ( just an opinion) Locals usually know best, some say. Try Iron Rock offroad, instead, or one of the other Jeep Forum vendors. IRC usually gets high marks from JF members.
RE: Gauge cluster lights. Might be the plug or even the headlight switch. Others know more.
Have fun fixing her up !