from someone whos actually converted a obd0 car with a obd1 motor, you will need:

the conversion harness-about $100
obd1 ecu-about $100
obd1 dizzy for your motor-about $100
obd1 4 wire oxygen sensor-about $100
then you will need to wire it all up.-about 1-2 hour depending on your skills.

check www.rywire.com

they sell all the shit necessary.