Touring last summer, no more than 5 days but quite places, I tried a similar set-up to the one Pedaldog suggests: 2 front panniers, barbag, saddlebag and tent bungeed to rear rack. This gave a much more solid, stable feeling than using rear panniers.
For a long time I was shy of barbags, thinking they did not justify the expense and would be uncomfortable. The Ortlieb Classic I bought last summer was one of the best cycling buys I've ever made: plenty of room, easy to access, absolutely waterproof. Fitting the mounting is a bit fiddly but did it eventually.
I'd certainly recommend trying the setup you suggest in the first post