With MC fenders you can fit 33's with no trimming and 35's with some slight trimming in the rear all on stock suspension. But if you're looking to save up some money first, I'd go for a 2.5"-3" lift then get the fenders. But if you've got the money to ahead and go for the fenders or a nice lift like ones from DPG Offroad. Either way it's your jeep. Just have a plan for it.
But if you plan on going up to 35's there's alot that has to be upgraded first before you can run them properly. If you don't upgrade things like axle/axle shafts, steering, brakes, etc. you run the risk of getting in an accident on and off the road. Just my two cents.
1998 TJ, 2.5" OME springs, OME N66 & N67 Sport Nitro Shocks, 33x12.5 Goodyear MTR's, Metalcloak aluminum arched fenders, Metalcloak aluminum front bumper, thedirtworx tire carrier, Warn xd9000i synthetic line and TRE Safety Thimble II