Cheers Nige,
I have since bought one from ebay.de part no 307 329 074 IIRC, the link I showed you before (same one as alfiejets posted above) says the ballasts are all the same just different PN's so I'll see if the one I bought does the job.
Bought an ignitor from ebay.de as well, so just need headlight now. Have found somewhere that sells the headlight (no ballast etc) for £189 which looked like a decent price... may just get one from them.
Alfiejets, I PM'd you.