In an attempt to distill all of the information available on the recommend items required to perform a tune-up on an XJ, here is everything I have gathered through my own research and some fairly extensive forum mining. Please feel free to add any recommendations and/or personal experiences to make this list as exhaustive as possible.
All items are for a 1996 XJ Cherokee Classic, though they should work for older model XJs, and may work for newer model XJs unless otherwise noted.
Champion Copper P/N RC12LYC
US$1.99 per (AutoZone)
The AMC-designed I6, as well as it's Chrysler improved variants, seems to run best on these basic factory-installed plugs. On top of which, they are significantly cheaper than other "Platinum Grade" plugs on the market. Often held in stock at most auto parts stores.
Bosch P/N 098284
While not all wiresets are created equally, they all serve the same purpose, and that is to deliver a charge from the distributor to the spark plugs. With this in mind, a Bosch wireset is recommended not because of any particular experience or function, but rather because they are a fairly basic, middle-of-the-road wireset, and are widely available. Essentially any wireset will do, but it is generally recommended that one not spend too much (for fear of wasting money on insignificant features) or too little (for fear of sacrificing quality for savings) on these essential electrical components. Often held in stock at most auto parts stores.
Accel P/N 120330
US$16.99 (Pep Boys)
This distributor cap features brass contacts, as opposed to the copper contacts of the Duralast cap. Additionally, in the case of AutoZone anyway, the Accel cap is actually US$1 less expensive. However, this product may need to be special ordered, depending of availability.
Accel P/N 130330
US$10.99 (Pep Boys)
This product was chosen simply due to the fact that it is from the same manufacturer as the chosen distributor cap. This product may need to be special ordered, depending on availability.
Upstream (before catylitic converter)
NGK P/N 23121
US$58.19 (NAPA Auto Parts)
Downstream (after catylitic converter)
NGK P/N 23014
US$60.76 (NAPA Auto Parts)
While Bosch manufactures many fine products, to include oxygen sensors, theirs do not fare well in Jeep vehicles. This is due to a higher required voltage draw in the heating circuit as compared to the factory-installed NGK (NTK) brand sensors. This causes the Bosch sensors to take longer to heat up, and may affect the OBD computer. Note that the prices are taken from NAPA's website, due to local availability. They can be found for US$48.99 and US$51.99, respectively, at www.summitracing.com
, but with a Delivering and Handling Charge of US$11.95 and estimated ship date often 2 weeks out, NAPA may be the best option when considering convenience. These items may also be purchased at the dealer, but due to the vagaries of dealer pricing depending on location, local taxes, and other factors, that option is not discussed here. Often held in stock at NAPA auto parts stores.
Az P/N FF676DL
Simply a widely-available inline fuel filter. Often held in stock at most auto parts stores.
AMSOIL P/N EAA29
This air filter comes with a recommendation from the comments. Good for 100,000 or 4 years, which ever comes first, and a price point at just under twice what an average conventional cellulose filter would cost, AMSOIL air filters purport a more efficient nanofiber techonology that only requires a simple wipe-down and dust-off once a year. Unfortunately, this item may only be available through order (http://www.amsoil.com/catalog.aspx?code=EAA29-EA
Again, please feel free to add any notes or comments to improve this list.