You definitely want the 90-93 version, because that's what matches the ECU harness in your car. I am assuming that as part of the 1.8 conversion, you moved over your old 1.6 injector harness and are running the 1.6 coilpack.
You will need to make a modification to the daughterboard in the MSPNP to enable variable TPS. This is documented here: http://www.megasquirtpnp.com/models/...m#Section_Five
This of course assumes that you're keeping the 1.8 TPS, which would be a good idea. If you do that, you'll of course need to make a wiring mod to get the new TPS +5Vref and GND, as well as bringing the signal into the MSPNP. Search some of my recent posts, I know I've described within the past month or two which wire is which on the TPS pigtail.
Having swapped the 1.8 TB, you'll need to change the IAC parameters in software, but this is well-documented. Just copy the settings out of DIY's basemap for 94-95.
That's about all I can think of at the moment.
edit: Here's the thread which describes what the various wires coming out of the TPS harness are for.
The pin numbers I state are relative to a regular MS DB-37 connector, but using these wire colors along with DIY's writeup, you'll figure it out.