I need a 6 litre beer keg. Does anyone know where I can buy one from shops or online in West Midlands.?

I don't know of any 6 liter kegs, but they make 5 liter kegs, called mini-kegs. You can generally get these from any local homebrew shop, or check out a href="http://www.midwestsupplies.com" rel="nofollow"http://www.midwestsupplies.com/a or even eBay sometimes.