If you're after a mechanic to do the job, possibly look for someone who specialises in Saabs. Pretty much all Saab V6s are based on the Opel/Vauxhall units. They might not like to admit it, but the truth is they are and the 900/9-3 was based on the same platform as the Vectra.
I think the biggest issue is that the intake manifold pretty much has to come off and from what I've seen, on the Y26SE and the succeeding Z32SE engines, that doesn't look like a 5 minute job.