You may want to look at the Corbin bags before you spend the money. They look great, but are way too small.
I can get a 3-overnight ride out of them. They rock for day-to-day. Can
mount a Givi case to the rear rack for longer...

I like to stop at produce stands and get peaches and cantaloupes... a
big fat cantaloupe is too wide to fit

...
-Mike "medium sized ones fit..."