Test ride, test ride, test ride. Get yourself on as many different brands and test ride them. They all have subtle geometry differences that can make all the difference when you're riding. Also take into account the service at the shop. I recently bought a fitness bike myself. I had my heart set on a certain Fuji until I was treated poorly at the shop. In the end I bought a Cannondale because it was the most comfortable and the lbs treated me very well when I went there to browse. Eventually you'll find the right combination of comfort, features, service, and price.

Carbon forks do help absorb road buzz, but personally I haven't really noticed a difference between my carbon fork road bike and alloy fork Cannondale. There's a caveat there though, as my road bike is running 28's and the Cannondale is running 35's at less pressure. Just my $.02