There has been a huge rush for booking the .co domains, which was recently relaunched. People who got their .com names earlier are booking the .co names to protect their brand names and those who missed out are now catching up by getting the .co names.
However you should really focus on getting the domain names that include your keywords. While different people have been saying different things, it is a proven fact that keyword rich domains get a preference in the search engine ranking.
We have a few .co domains on sale here. If you like one or a few of these, make an offer. We seriously consider all reasonable offers.