Hi Jen, here's my setup using Ortlieb bags-100% waterproof and tested by yours truly for proof. I don't tend to do more than dirt roads loaded up and this has worked well for me for almost 20K of touring one and 2up.
I wouldn't go Pelican for panniers due to weight but I like the lockable one for a top box. Usually it has my cooking stuff but I've travelled with my computer in there with good success-multiple drops, no breakage.
The duffel holds tent and sleeping stuff, running 2up it rides on the top box.
cozy but it works, helps if you like your passenger