I have the harness from the donor but I forgot to get the fuel pump and main ignition relays and also the alternator wires. Can I source them from another vehicle to make it work?

Alternator wiring you use the recipient vehicle's alt wiring and adapt the EJ wiring to it (some EJ alternators require and ing trigger wire).  You can choose to upgrade the main wire if you wish.

Fuel pump wiring and main relays can be used from another EJ vehicle. Afaik they're all basically the same.

Cheers

Bennie

I have a 99 I can steal the wiring from you think it would be the same as the 97?

There could be slight differences but you'll work them out. 

Cheers

Bennie