there are a few companies that make rear racks that are regularly used on cf bikes, mount onto the brake caliper up top and use a skewer on the rear rear below, like this one, which can be bought for $40 can.
Streamliner Racks - Racks - Products - Axiom Performance Gear
you can use whatever panniers you want, but these ones are very light and may be enough for clothes and such that you need.
Arkel - Dry-Lites - Ultralite Saddle bags - ONLY 454gr!!
add a handlebar bag or something and you are perfectly set up for what you want to do.
if you find you dont like doing this sort of thing, sell the stuff used afterwards, but even new we are talking $130 for rack and bags.
I own these bags and they are completely waterproof, have a few niggles but that comes with the light design (go on with velcro, but in my experience stay on bike perfectly well)
keeping the load weight within reason, there is no reason not to have a fun light tour with your bike from motel to motel.