I would replace the panel filter in the air box for a performance one from either ITG or MapTun, then get a remap done by somebody who understands Saab's funny little ways! You should see about 200 -205 BHP for a stage 1. It is also advisable to have a service done on the car before you get the remap done. Expect to pay anywhere between £200 & £400 for the remap plus between £35 & £50 for the panel filter. Modifications to the exhaust will not be required for this stage.