Hey johndo1,
I run a company called Better Brief, we are a small web development company that has been running for about a year and a half. We are based in London, UK and have worked with clients remotely to produce many sites.
We have been using SilverStripe for about 8 months and are very familiar with it, implementing lots of different modules and different bespoke features for clients. We have made use of a wide variety of aspects available to us as developers which make it far easier for users to manage the site in the CMS.
Our team also includes a programmer who worked at GPMD who are the official SilverStripe partners for the UK. So we have plenty of experience and expertese with SS.
If you give me an e-mail i can give you some more info.
EDIT: REMOVED E-MAIL ADDRESS
Dan