32 years old, your mechanic is spot on. New belt, water pump and tensioner. You can buy the complete kit, OEM Aisin parts, from Rock Auto for a good price. Your mechanic will charge you about 8 hours for the job. Plugs should be fine, but i would do coolant, oil, filter and brake flush just becuase of the age, unless you know when they were last done. A few treatments with in tank injector cleaners and a then new fuel filter would also be a good idea.