Could you post a picture of this "rare" car. I would like to see it. The GSX and GS-T are turbocharged. Is yours turbocharged? Does your Avenger have a 420A or a 4g63? The 4 cylinder Avengers did come with 5 speeds. I am curious.
As for the gauges, if they are glow gauges you should hook them up to a lead wire from the old gauge cluster bulbs. That would make them come on with the normal light switch the same as the old gauges did.