Cinelli Radical and Radical Plus
Cinelli has a long and storied tradition of making great bikes. They have a classy Italian design and encourage a custom build, so making something special is easy.
The Radical frameset is £900 and the Radical Plus (a lighter version) is £1100 and can be a complete bike from £1500 and up. There are other, even more special options from Cinelli, but for a great Italian carbon race bike that won't cost very much, this is the one for you.