I would highly recommend Dual Flowmaster Delta series mufflers. I have them and they are great. I put a K & N cold air intake on mine and saw a difference. Brakes, I have Hawk HP Plus pads. Excellent stopping power and virtually NO brake dust.I put on 8mm Bosch plug wires and the Bosch quad 4 plugs. As far as the suspension, I put Eibach Pro Racing Springs on. It lowered my car about 1.5-2.0 inches and handles like a dream. I have not been able to find original factory interior parts either. If I find them , I will let you know. You can get the brake pads and springs from
www.neoncars.com. They are really cool there(I happen to work there.) We have alot of parts for other cars too and great prices.