I'm a complete numpty when it comes to mechanical bits on cars but even I changed my hatch over in 20 minutes, most of that trying to squeeze my 6ft 3" frame into the back seats to get at the tailgate hinges on the back of the roof. Once in, 4 allen bolts, someone outside moving the hatch into position then tighten the bolts up, Job done, cup of tea and pat on the back. Most of the later 944/968 spoilers were satin black so will go with any colour car, colour coded was an extra option I think. Got mine on Ebay but try the breakers though if anything like Douglas Valley they wanted £350 quid

Try also the specialist garages like JMG or Strasse, they normally have loads of s/h parts in stock. Jon Mitchell is having a big clear out at the moment so you could try him. Look in the Parts for sale section for his recent post.
Andy