In reply to kathrync:
If you join British Cycling (£15) you get 10% off at halfords. Given that they're currently doing 10% off anyway, it would basically give you a £1000 bike for £800ish, e.g.
The aluminium frame Road Team bike, is excellent value for this price (105 groupset, Mavic Wheels, BB30 bottom bracket):
http://bit.ly/hJx3NL
One of the befits of going for a 105 groupset over Tiagra is that it's 10 speed, so you can upgrade to Ultegra or whatever in future if you really wanted to.
I've just bought the carbon version and love it. One word of caution though - the Halford's build isn't brilliant (bit loose, gears not properly indexed, etc), so it's worth budgetting an extra £50 or so to get a proper bike shop to set it up properly for you