I can't recommend the Kata DR-467 enough. It's very affordable compared to the R-103. Not as tough but tough enough.
Fit my D80 + 10-20 + 18-50/2.8 + 50-150/2.8 + SB-800 Flash + 77mm filters when I was using a Nikon system. Has a "raincoat", can strap on a tripod, water bottle pocket, compartment for a small towel, extra shirt, phone, wallet, notebook, pens, cleaning essentials.
Oh and it fit my 15" MBP and its charger too!
Quite a heavy load but I was fine in the mountains, riding motorbikes on real tough terrain and all. I was on the rice terraces for hours in the rain and a little water seeped in. But I'm always prepared with some plastic bags, wrapped my mac as soon as it started pouring.
Sold it now that I'm using pancakes hehe.
Hmm I think it costs about $60 or $70 now.
While I wanted the R-103, it costs more than double
Tremendous value for the DR-467!