Hi Mike,
First place to try should be Vaio Support to see if they will sell you one. You will need to use the out of warranty premium phoneline 0905 0310006.
If that is not possible, I think you will need to import one from the US. Several places seem to have stock but this one advertises international orders: -
http://www.sparepartswarehouse.com/Sony,Computer,Part,146877213.aspx
