My dad had a CDA airbox on his spider, and to be honest we couldn't tell any difference except for the noise.
For a 1997 car you need a Squadra chip. Its an easy DIY fit, though you need to find out whether your car has the M2.10.3 or M2.10.4 version of engine management system fitted. As your car is a 1997 I would have thought it was the M2.10.3
.: Squadra Tuning :.