Ill be honest its far cheaper to "pass it" illegally than legally, or get a drivers license in a non emissions county.
Contact Scotty about chipping your OBD0 ECU and turning your O2 sensors off, then installing a cat i would call Mainstream Performance and talk to James or charles, that is you best legal option.
Installing a secondary O2 sensor will not pass you (long story) and youll still need a cat instaled