Double main column theme with no sidebars?

Hello!

I am wondering if there is any double main column themes available, i am starting a site that will showcase both ours and others work, so left column will be our work, right column will be others work.

These also need to be categorized, so if i select say Print in the top navigation, only posts in the category print will be displayed in both columns, this would interfere with categorization i guess?

I would also need ad space between the two columns and those fancy little boxes next to the posts with date, and category and such. Attached to the left side of the posts of the left column and attached to the right side of the posts in the right column.

Seen anything like it?

Sincerely Martin