I'd suggest a more traditional design. Jack Sobon's books feature a lot of traditional timber frame details. I especially like "Historic American Timber Joinery", which shows many examples of how to frame an overhang. It is available here from the TFG as a free download (
http://www.tfguild.org/joinery/joinery.html) or in print form here as a booklet (
http://tfguild.stores.yahoo.net/tifrbo.html) along with his other books.
Regards,
