Little Metal Men
I have only purchased a Ogre Maneaters from this company, but found the service to be excellent.
They are the only on-line retailer I have found that allows you to order a specific kinds of blister pack. All the other on-line retailers say that the miniature contained in the blister will be a random model, which is rubbish when you are looking for a specific miniature.
I wanted the Orge Maneater Pay Master miniature, which other retailer could not supply (not even Little Metal Men, apparently it is de-listed). A trip to Warhammer World will probably be required to see if I can acquire the Orge Maneater Pay Master.