Three really good plugs for your '98 TJ include the Autolite AP-985, Champion 3034, or Autolite XP-985. The first two are platinums that are good for 100K miles, the last is iridium which will likely perform well for 200k miles.
Yep it'd be good to replace the distributor cap, rotor, and wires too. For the cap and rotor, try to find replacements that have brass contacts. Those with aluminum contacts are cheaper and won't last as long.
For the ignition wiring, there is a lot of junk-science out there. The main thing to keep in mind is to avoid the so-called "low resistance" ignition wiring sets. Yes I know that low resistance sounds good but in the case of ignition wiring, it's not. In fact, the manufacturers add extra resistance to ignition wiring at additional cost to insure the wiring doesn't produce static/interference that can be heard on the radio or CB radio, or create problems for the ECM (engine computer). It actually costs less to produce "low resistance" wiring which just creates noise & problems. The best performance/best quality ignition wiring you can install is actually the OEM stuff that you can get from the dealer. If you know what you're looking for, it's possible but VERY difficult to find good quality ignition wiring at the auto parts store. Personally I would go right to the dealer for the ignition wiring, the stuff sold in the auto parts stores is often junk and at best, a real crap shoot.