Well there's a few factors that will help determine the lift.
What type of wheeling do you plan to do??? What type of terrain in your area or places you plan to go??? Will it be a daily driver, so how much street driving??
The biggest thing I can suggest, is get out and wheelin it stock to see how everything performs and learn more about your Jeep and it's abilities in stock form. They are very capable.
Depending on what youplan to do, the common lift is usually 2" or 4" and will fit 33's or 35's on 4" with some additional upgrades.
98TJ / Hi-Lined / Zip Lockers / 35s
Don't mean to hijack the tread but will you need to address anything if I were to put a RC 3.25" lift on my tj?
It all depends on how you get the height. If thats 3.25" of suspension lift you are getting into the area of needing a sye and a few other goodies. If thats 2" suspension and 1.25" BL with 1" MML you should be fine. I ran an OME 2" suspension with 1.25" JKS BL ans 1" MML on my old TJ and it was a perfect fit.
On a side note you should check out northeastjeep.org its a local club that could help you out quite a bit if you are interested in off roading trips ect.