I never purchased the stage 1 because I am buying a VR4 and selling my car. But you might try parts trader and there is one for sale in the Sale Wanted section.
97 Eclipse GS
OBX type H Cat-Back Maxspeed Short Ram intake Pacesetter header Neuspeed Springs 1.5 inch drop Progress Tech camber kit 16" Konig Monsoons Coming soon (HRC Stage I)