I can vouch for Piero Cossu at race-pro.nl who build a lot of the European Superstock bikes. http://www.race-pro.nl/index.php?main_page=index&cPath=76&zenid=bcrt0s2jknnhfb21cr0qui9096 I've had quite a lot of stuff off of him last year and he was excellent. I was quite suspicious to start with as I'd spoke to a few dealers in Europe and they warned me against him but after spending a considerable amount of time discussing things with him and others I came to the conclusion he only had that rep because of upsetting the over priced dealers with better deals.
Mssperformance are selling them superstock preped zx10rr https://www.facebook.com/mssperformanceltd/posts/1675384565846421
Last year that, mate. Just sold his BMW superstock a couple of weeks back. Don’t know what /if he’ll be racing next year.