So, a titanium canister would seem to be the answer. But....there is no such thing. As common as titanium has become these days, it's still a pretty expensive metal, so a whole bucket made out of the stuff likely would cost $500 or more. Plus, it can't be cast like most metals, nor can a canister be machined out in a cost-effective manner. So it's just not in the cards. In lieu of such an exotic device, you're left with traditional bear canisters such as Garcia Bear-Resistant Container ($78), which holds up to six days' worth of food if you pack with excruciating care and use foods such as rice that yield a lot of volume when cooked. Made of ABS plastic, the Garcia container weighs a little less than three pounds, so in itself it's kind of a load.
My only advice is to figure out a way to pack a wire and a slingshot. Use the wire to rig a hanging device as high as possible, then the slingshot to sling a weighted line over it. Make the best bear-proofing device you can, be cautious with your food, and hope for the best.