Almost all major bicycle companies have a cyclocross line. What you can do is get on their websites and look for a "Dealers" page. Those shops will either have the bike in stock or they can order it. That's what I did when I bought mine.
Some companies: Kona, Specialized, Felt, Trek, Cannondale, Bianchi, Surly, Giant...that's all I can remember.
To pick the best bike for you focus on how it fits you, and use the reviews as a guide. roadbikereview.com and mtbr.com have lots of reviews on bikes and components.