I use a Madone 5.2 for my commute. It is comfortable.

There are recent posts discussing mounting racks on bikes without braze-ons. I have used clamps with rubber inserts for my old bikes without braze-ons.
http://www.bikeforums.net/showthread.php?t=580520
There are also seat post racks.

I use an Osprey Atmos Backpack. I have removable fenders and a mirror on my commuter.

I'll post pictures of my bike on this thread later this week.
http://www.bikeforums.net/showthread.php?t=579479

Ride what you got and have fun!