You got quite a few good selections to choose from-- All the reputable vendors have good carbon fiber road bikes in that price range (Trek, Specialized, Cannondale, etc.).

I think your best approach would be to look for a bike with a setup that you like (geometry, handlebar setup, components, etc.).

Me for instance, when I went shopping for a carbon bike, I knew I wanted straight MTB-style handlebars with rapid-fire shifters, and at least Ultegra components. Ended up buying this carbon-fiber bike and I love it (photo of my baby strapped to the back of my car): http://priuschat.com/uploads/post-29948-1190659647.jpg

So figure out what features and components you want, and hunt accordingly. Once you decide on which specific bike you want, go to a bike shop that carries it and have it fitted to you. Good luck!