Enterprise and Beach are the only 2 themes for free blogs provided here at wordpress.COM that meet your criteria.
Are you referring to a wordpress.COM blog? I'm asking becuase you have not linked your blog to your username and you have not provided the URL for the blog in question. If you are reffering to a free blog from and being free hosted by wordpress.COM and want to link your userbname to your blog it's easy to do.
Dashboard -> Users -> Personal Settings -> then scroll down to Account Details. Then scroll down to where it says ‘Website‘ select the URL for your primary wordpress.com blog starting and then save changes.
Now every time you sign into the forum we can all click on your username and your blog will be linked to it. And every time you leave a comment on a blog your username can be likewise clicked and your blog can be instantly located.