Would units from a Classic STI Saloon fit a Classic WRX wagon? And would I notice much difference from the standard shocks?

 

I am pretty sure they will swop straight over.
If the Sti units are in good condition then the difference will be very noticeable.
You should add Whiteline roll bars while you are at it and REALLY notice the difference.
Get it aligned by someone who knows what they are doing, ie Powerstation advertising above this thread.

You will have a nice Wagon afterwards.

Graham.

 

cheers graham, I may just give them a try.