Tumi makes a couple of nice leather options in the Alpha collection as well. The slim is pretty small but might be what you are looking for in overall thickness. The expandable slim will cover your needs well and give you room to grow when needed.
I have both the leather and ballistic version of the slim expandable but don't carry either. The leather looks great but adds ~1.5 lbs to the overall weight of the bag. I chose to go another route with this vertical tote.
http://www.tumi.com/product/index.js...ndSrc=paramNav It gives me all of the room I need, looks rather european and keeps me from loading the darn thing up. Bad back and lots of miles = light brief.
http://tumius.imageg.net/graphics/pr...7269enh-z8.jpg