The fuel filter is a sock-type filter on the fuel pump itself and is designed to last the lifetime of the fuel pump; generally they are only replaced when the fuel pump is.
Spark plugs have a 105k replacement interval - you probably don't need to touch these unless you don't want to. If you want to replace them anyway, you can obtain 6 NGK PLFR5A-11 (6240) spark plugs for $40.54 + tax at
Advance Auto Parts if you order online with discount code
RETMENOT123 and pick-up in store. PLFR5A-11 are the spark plugs specified in the
MA section of the factory service manual.
The thermostat isn't a maintenance item usually - I would just replace it when it fails.
Draining & filling of the radiator can be done yourself. See
MA-16. Use Nissan long-life blue coolant. You can obtain a jug from your local parts department. Be sure to use distilled water
only if the coolant is not premixed.
If you have not yet changed the differential fluid, brake fluid, or power steering fluid, you may want to think about doing those soon as well.
Information on changing the diff fluid can be found in the MA section of the FSM. The capacity of the front differential is 0.68 quarts; rear is 1.48 quarts. You can purchase 3 quarts of
Mobil 1 75W-90 gear oil at AAP for $22.97 before tax with coupon code
VISA, then pick-up in store.
For power steering fluid, use a turkey baster to suck the fluid out of the reservoir, then add PSF or preferably, synthetic ATF. Drive around for a couple days and repeat this process a few times to exchange most of the fluid.