Bike shops in UK

Hi all,

I intend to go to the TDF2004 and after that head across to the UK for
a week no cycling just looking around. Not sure where I'll be staying
etc... First trip over there from Oz.

I'm after some good bike shops to get a pair of wheels built using
Campag hubs. I'm also thinking of getting a new Chorus groupset over
there and getting the shop to put it together for me.

Any advice or recommendations, locations would be appreciated.

TIA
Colin