I've used blackcircles on previous cars and had 2 good experiences of their fitting centres (which are just local fitters to you off their list) and 1 bad where I was low on the pecking order at the fitters because I didn't buy the tyre through the fitters direct.
If I were you I'd buy this one off ebay (offer them £99 inc delivery) then go to a local tyre fitter with a good rep and pay £10 to get it fitted and save some coin.
*Pirelli Euforia 205/45/17 RFT* *BMW/Mini/One/Cooper* on eBay, also, Tyres, Car Wheels, Tyres Trims, Cars, Parts Vehicles (end time 10-Feb-08 20:00:00 GMT)