depending on the size of your luggage and the availability of a rack on your bike, I think one of the following options is to preferred for a biking/hiking trip:


panpack

bike nashbar

Arkel Bug

Ortlieb carrying system to use with their waterproof panniers, small and large

the latter is the one I've used (because I rate the waterproofness of the Ortlieb panniers at the top of my wish list), and it's ok as long as you don't carry too much weight (5-7 kg); if you add some padding at the bottom of the pannier you might be able to carry more weight without discomfort