Plastic bikes
I just finished a 1000k this weekend on my main Randonneuring bike, a Trek Pilot 5.2. I've done a series on it and the Cascade 1200. It' got eyelets for fenders, which I do run most of the time here in the Northwet. I've also ridden several of the shorter brevets (100,200,300k) on my Trek 5500. For hauling stuff, I carry a Jandd Large seat bag. Typically, it weighs less than 10lbs and I don't need to add any rack for it (and the extra weight).
Don't let anyone give you too bad of time if you ride plastic, Jan Heine Gives me a bad time about my plastic bikes, but he'll grab it's wheel just the same.
I've ridden steel in the past, but prefer my carbon. Ride whatever you like and feel confortable on.
Brian