Welcome to the BB and 164 ownership
It would help us if you add a signiture to your posts including you year and model.
I suggest you follow the advise given and check things out before wholesale changing out parts. Check the resistance of wires and distributor cap. Check your fuel pressure at the rail.
Chain parts stores will have plug wires and distributor cap, but probably not the thermostat. It would help if we knew where you are, but some places to get parts are IAP, Centerline, Jason, Trail Auto, Difatta Bros, APE and the list goes on.
Red 1991 164S, Black 1991 164S, Red 1987 Milano, 1972 Berlina, 1973 Berlina rebuilding SPICA engine