I'd stick with "if it ain't broke don't fix it." If you are really concerned, take something you can whack the starter with if it acts up. That should work well enough to get you through to a replacement -- when needed.
Keep in mind your vehicle is likely 25 years old. Get in there to replace the starter, and no telling what can break during that repair. I do suggest checking your water pump, specifically, the "T" for your heater at the firewall, all your fluids (change if necessary, top off otherwise), all your belts and tensioners, your tires (wear and air pressure), and your brakes.
These are just good things to check in general, but especially before a long trip.