||120K generally adds new timing pulleys and a new water pump. Everything else is pretty much the same. The parts should run about $250, imho it would be worth the added peace of mind, especially if you plan to keep the car.
Others may suggest you evaluate how well the pulleys spin and if there is any resistance, noise, or slop in the pulley bearings and replace as-needed. The water pump is not that difficult to change so if not leaking you could let it go and just watch for any puddles on the floor. Definitely have the coolant flushed and change out the thermostat. You may also want to reseal the valve covers while you're in there (at least check carefully for leaks).
The most critical element is going to be the timing belt.