All depends on you and what you plan on using it for. If its your daily driver and only hits the trails on weekends or maybe once a month I wouldn't go bigger than 33" tires.
Lots of good kits out there, read some reviews. Its hard to get opinions about what kits are better. I had a skyjacker in my TJ and hated it...Then again another guy might love his. My XJ had a Rubicon Express and I really liked that one. I'm looking around at lifts for my 88 wrangler and leaning to OME or BDS. Read lots of reviews, see what is a more complete lift or what else you may need and pick