PRS in liverpool has everything i need :)
Even has a box of disassembled tape decks with the motors and play head, random heatsinks, motors and everything else you can't thing of.
plus its fairly cheap. ;D
I dumpster dive http://www.circuitbenders.co.uk/forum/index.php/topic,749.0.html with the sole purpose of scavenging electronics devices of what ever I need.. When i need something very specific I use a shop in town.. VERY expensive and the owner is very arrogant.. Service is crap.. Only place in town..
There's an old electronic supply place in my town that I go to when I need IC's quickly, but otherwise I just order from Jameco or Mouser.