+1 on looking in the commuting forum.
If you want drop handle bars and disc brakes, look at touring bikes.
Giant offered the OCR Touring bike with disc brakes in 2004/2005 but I don't see it on their website in the 2006 models. Maybe your LBS has a leftover or can order one for you.
My commuter is a cyclocross bike with drop bars and cantilever brakes.
You can see pictures in my signature.