In reply to dcsevier:
Helmet cover (look at Osprey designs) is a must, but I'm not sure how many fishing men would be glad to see such feature.
There is no do-it-all bag. I moved into a new flat recently and all my stuff fit into all the bags I had (okay, needed one bin bag for some clothes, but that's it). I am also looking at buying two new rucksacks. Tell me that I'm crazy and I'll get another one!