I'll go with the tankbag...and the tank on the '01 is metal right? Anyways, I have a Nelson-Rigg magnetic bag for mine. Got it off of New Enough on a closeout, but they're currently selling for $41 which is extremely reasonable.
http://www.newenoughhp.com/nelson_ri...k_bag_page.htm
The magnets are powerful; that thing does not shift. It'll hold a ton, especially if you let the expansion zippers out. The build quality is great, and it really maintains its form over time. I've taken some long trips sprawled across it, and it doesn't look splayed. The clear map case on top is nice for a quick reference. If I decide to do any touring in the next few years, I'll be getting the soft luggage for the rear as well as I like the pricing & quality.