Hi,
I've done quite a few backpacking trips around here where wet wadings is not an option and even haul my float tube each year (a Woodriver Swiftrider at 4lb 5oz is not too bad if you go for serious lightweight camp gear). As for waders, the cheap RED BALL coated nylon are quite light and I found them quite durable but they are hard to find. Anyway from my gear list (I count every oz. that go in my backpack) I could say that the hipper (Small) weight 8 oz. and the full waders 14 oz. Add to that a pair of neoprene socks (4 oz.) as the foot is the same material as the upper. With the sock your could wear a pair of sandal over and not worried about putting a hole in the foot area of the waders as the socks take the beating and you could wear the sandal around camp. That was my set up for years and I was quite satisfied. I still use them but since I couldn't find backup, I pick up some Simm's Travel waders when they got discontinued last year (paid 89$). They're 16 oz. and I add a pair of neoprene socks for the same reason listed above. For now they are great but I don't know about durability... About the same time I bought some Simm's hippers (also discountinued, around 50$) They are great (even bought another pair just a few month later) but at 20 oz a little heavy for backpacking and since they come with neoprene stockingfoot that leave the sandal option out and make them a little bulky. But I think Orvis made a Travel boot that is quite light. That I should investigate... Anyway, that is the best set up I could find at this time. Backpacking with a fly rod is great but you have to do your homework... Go lightweight in all aspect without compromise security.