[JayJay]

I'd suggest a water pump, radiator hoses, fan belt, a starter bendix assembly and bulbs (headight and taillight) in addition to those spares already mentioned. I also carry a camshaft timing gear, a complete engine gasket set, plus gaskets for the sediment bowl, radiator cap and gas cap (experience talking here...). For tools I carry a 3/8" socket set, a set of adjustable wrenches, feeler gauges, some pliers and screwdrivers, a water pump wrench, a Nu-Rex timing tool and a digital VOM. I also carry a container of mechanics hand wipes and a roll of blue paper towels.

There are some new, small, relatively inexpensive battery-powered rechargable air compressors that will make your life oh so much easier. You can top off your tires from the comfort of your hotel parking lot and not have to search out a grungy old service station. Many of them also double as a jump box.

NK has the right idea. Accumulate stuff based upon your experiences, that way you'll know you have it.