Update :
did some ringing round today and after ringing some local indies that blatently didnt want to touch it (sucking through teeth and "you'll know that'll cost a fortune mate") etc.. i came across one recommended to me by a taxi driver friend.
Gave the guy a ring and he was a thoroughly decent bloke. He worked for 12 years at one of the local garages i know, but left to set up his own garage when they became just a tyre and exhaust place and didnt want to do any mechanical work.
He owns a lancia delta integrale stripped out track car as a project / toy and loves getting to work on more interesting cars than just changing clutches for knackered old taxis. He's suggested we send the clutch off to CG motorsport in leeds
http://www.clutch-specialists.co.uk/
They can supply a new clutch cheaper than the £350 that vauxhall want, or alternatively they do custom clutches. May well be worth them rebuilding my clutch stronger as they do bespoke work. Ive actually driven by this place before and they've got 2 Skylines outside all stickied up and they sound mental when fired up, so no doubt they've got silly power to demonstrate their clutches. Their also an authorised Exedy distributor so they should be good.
Anyway, cut a long story short the guy was really enthusiastic, and sounded really knowledgable. Was telling me about the Vectra 3.2 GSI they had in recently that they had to strip down etc.. But he reckons it will be more like £400 - £500 as opposed to £800 and they can collect. Dropped the keys off today and they're picking it up for me and everthying.
May yet get to keep the car as shes calmed down a bit now that the clutch is getting sorted, and not nearly as expensive as what vauxhall were quoting.