Thanks for the reply Boostin, very informative.
Few questions though:
1) Why do you reckon the ECU would need replacing? The reason I ask, is that if I were Subaru, it would seem more cost effective to me to make all the ECUs with the appropriate inputs/connections for cruise control if a model has it as a factory option. That way you can mass produce 10M units of one rather than 5M of x and 5M of y. Of course if you're sure there are two different ECUs (one with CC support, one without) then I guess I'm willing to eat my shorts.
2) I guess the same question goes for the wiring harness - again, it would seem more sensible just to leave some connections "unplugged" rather than produce two different harnesses.
3) Does the Body Control Unit contain functionality for cruise control? I thought that was for central locking, windows, courtesy lights etc
4) What do you mean by dash cluster?
5) Why do you think the keys might need replacing?
Any idea on approximate price I'd expect to pay for above parts from a wrecker?
PS don't want to go the aftermarket route anyway.
Cheers,
Eddie