The sky is the limit for XJ mods. There are a ton of things you could do... question is, what do you want? Bigger tires? Some lift? Fresh paint? Performance mods? Window tint? Coffee Can exhaust? Stout bumpers? Offroad protection?
As for painting, if you own or know someone that owns an air compressor and automotive paint gun, its not hard to paint your Jeep. I did it to my XJ years back. You sand down the original paint (wet sanding), let it dry, tape off the windows/etc., spray primer and dry, wet sand again, spray your paint, wet sand again, spray your clear coat, wet sand and buff. Then you let it sit in the sun for a few days to bake (easy to do here...it was 110 out)
Took me and a buddy two days to do mine. Came out great...Solar Yellow.