You won't need a new wiring harness since your car is an EX because the wiring harness is already wired for Vtec and the knock sensor. As far as electronics, you will only need an ECU, and an OBD2B-to-OBD1 jumper harness too but only if you want to convert to OBD1 and run a P-28 ecu etc... If not, find a P2T ECU from a '99-'00 Civic Si and run that. Or you can also switch your fuel pump pin on the wiring harness (I believe its pin #15) and run any OBD2B Integra ECU. I would run a P73 ECU from an '00-'01 Integra Type-R.
Mounts, you should only need the rear bracket.