There's nothing much to do other than regular maintenance. Check spark plugs and coils. What's the odometer value. These V35 engines are very realible if you treat them right.
What's the model? 250GT? and YOM?
Depending on the YOM. it can be direct injection or port injection. There's a tendency to carbon built up in DI. if the car has done almost 100k. You may have to clean valve body and intake.
About parts. Nothing to worry. The site i mentioned even carry body parts. Even little knobs in interior. Also there are plenty of parts in japan. If you know how to get it here.