What about the Flipside 400 AW ? Or the new Pro Runner series ? You could go try the Pro Runner 300 AW, or the 350 AW which also suits a laptop.
If I were you, I'd look at the biggest Flipside (400 AW...AW is really handy!) or the Pro Runner series. If price is not a concern, the Vertex AW series are outstanding bags too (but rather pricy - at least, the 300 AW is). The latter is especially suited to people trekking with a lot of gear.
SSM/NEX-5/18-55 OSS/Lowepro Pro Trekker 600 AW/CompuTrekker AW/Nova 140 AW/Street & Field gear/Toploader Pro 75 AW. And a huge wishlist...My photos on Flickr...