Pig9r,
I bought the metric type socket. Actually it's a BMW design, I think, that became a European standard.
Then i bought a adapter so I can use American accessories as well.
IMHO the BMW socket is a superior design to the American version in that the BMW locks in place, where the American sort of stays put by friction.
Here's a link to the Company I purchased my sockets. Not sure if they are cheaper else where cuz I respected the fact that this company offered excellent explanatory information and history of the BMW sockets I decided to buy from them. Very fast shipping. Here's the link: Link Removed