Just done exactly the same myself Terry. Fortunately a mate of mine owns Sydney Street bikes in Brighton so has helped me make sure I am on the right bike as its a minefield out there. Like you, I was looking to spend £600 to £800 max. I was looking at specialized, and also nearly bought a Cannondale CAAD 8, but in the end plumped for a Scott Speedster, and got a blinding deal on it too, so I had some change. The main thing is to try them and see what is comfortable for you, as they do differ. With the Scott you get a really good frame and shimano stuff, and its a good base to upgrade it later if needed. Once you are sorted we will have to get out for a ride, though it will be a bit quieter and slower than our normal convoys!!!
This is the bike I have just bought and is being delivered today, Yeeee haaaa!:
http://www.westbrookcycles.co.uk/ima...1-99224000.jpg
If you need Chris's (Sydney Street bikes) number let me know. He is really helpful.