Spring Sockets

Dear All,
I have recently been looking for some spring sockets but have
only found one (Dutch?) company - Lesjofors - that sell this product. The
problem is that it has a minimum order of £50 and I'd like to ask if anyone
knows a company, preferably within the U.K., that sells this type of item
that has either a lower minimum order charge or none at all. I simply
require an extension spring to hook into one of these sockets at both ends-
and then screw the socket into some MDF.I would be very grateful of any
information.
Simon Griffiths.