Best place for San Shou in London is the Shaolin Temple UK people who have a permanant "temple" and consistantly put up the best San Shou fighters in the UK.
Saying that, you will pay a lot for the training and I think that you have to go through a "traditional" programe prior to being able to attend the san shou classes.
Next best would be Neil Rosiak of Renaissance Tai Chi who has a permanant base at (I think) tower bridge.
If you are in the UK now and are interested in San Shou have a look at Pro KouShu that has a new league starting in november.
http://www.pro.kuoshu.co.uk/
LOL.. really, what else did you hear?.. did you hear that he was voted Man of the Year by Kung-Fu Magizine?