low weight/cost options
The Scrambler is rated to carry 440 lbs total (passengers,fuel,gear,etc...) so the lighter the add on luggage systems the better. Most people aren't in the position to drop a few grand on luggage right now - I sure as hell am not, so I figured I'd share what I've learned the hard way.
Last November (when I got canned) I had to solve the problem of carrying everything I needed for two week trips, camping all the way, with all the tools and spares a bike would need in remote locations. I didn't want to spend anything, or as little as possible. After some serious thought I came up with this:
I had a laptop bag that I used on the passenger seat, a expandable tank bag (Nelson Rigg CL650 $62 delivered) that I had bought on "newenough.com" that really worked as a windshield, and a Hepco & Becker tail rack. I tied the tent, ThermaRest and sleeping bag to the rack with a nylon strap that I found attached to a hand cart.
By the second trip I had learned a few things about packing for long trips. I would use the lap top bag behind me for the tools, spare parts, etc (metal/heavy dangerous stuff) and the tank bag for the clothing/light stuff. I did this in case the bike went down - I didn't want to be hugging my tool kit and spare parts as I kissed the ground at 70 mph. I also stashed my rain gear between the rear bag and the sleeping bag. The bungee cords holding the bag on were enough to keep the gear lodged between the bag and the tail rack stuff (see pic below). This made the bags less packed (or I could carry more) and I had quick access to the rain gear. Plus, it pushed the bag just far enough forward so that it acted as a back rest.
As far as rain, the compression sack seemed to keep the sleeping bag dry. The tent never got wet from the rain on the road (it got wet once or twice when I put it in the bag while the tent was still covered in frost). And the tank bag came with a rain shield that worked pretty well. I did pretty well with this set up.