Illy, or Lavazza if you have an espresso machine.
If you've got a whittard's near you why not go in and get them to grind you some beans
Alternatively get one of these and buy your own beans:
http://www.amazon.co.uk/Dualit-Burr-.../dp/B000094U5T
Then grind them fresh as you need them
The next step after this is to buy green beans, and roast them yourself in the oven (WOW!)
(the smileys indicate garanteed satisfaction levels)