The BCS fits that criteria and is based of the george tarp with some modifications.
More information is here
http://seekoutside.com/backcountry-shelter-2/

and here is a review
http://hillpeoplegear.com/Forum/tabid/679/forumid/23/threadid/1176/scope/posts/Default.aspx
It actually opens up into a tarp or accepts an add in panel that expands it to 100 + sq feet.
We are working on a smaller trekking supported pole version as well, that should have a review available.
Sorry for the commercial post
Kevin


