Hey guys- cheers for the feedback and suggestions- some pretty awesome info in here now.

I'll keep it simple, water proof and quality: going with the Ortlieb Backrollers and the Ultimate 6:5L handlebar bag. Can't go wrong with those I think.
I AM used to using a closing lid flap on my current panniers but assume I'll quickly get used to the backroller "roll down to close" method.

And as I'm going to REALLY attempt to pack lite for this trip I'm also now looking at a Jetboil Stove, as my old school camping stove is just too cumbersome and clunky now. The Jetboil seem really squared away and compact/efficient.
I'm assuming I can easily find a store in Vancouver to buy a gas cannister for it as I won't be taking that on the plane..!

Training is going really well too now- to the extent that even after this trip I want to keep the routine up purely for health benefits. I haven't missed a day in 6 months and feel so much better for it.