If you are moving up to a rucksack, you can also move away from the idea of a specifically packaged survival kit. In a sense, everything you have with you, aside from whatever job related items like cameras, notebooks, measuring tapes or whatever, is along for the ride because of its utility in making your life comfortable or possible. I would agree with Chris that some kind of cooking container (my preference is for tough, lightweight aluminum) is a worthwhile addition. This can hold the burner head for a light weight cartridge stove. Add in a cartridge and you are set for fire starting and boiling water. I often carry a stove and pot, even for day hikes,
because of ecological and safety considerations involving open fires where I live. Throw in the other items that you would normally carry and you are set.

Think of your load in terms of a series of enhancements to the basic survival kit items. In a Altoids kit you might carry a condom, fish bag, etc. for an emergency water container. You can upgrade to a real canteen in equipping your rucksack. Similarly a mylar blanket expands to a tent, your basic knife is suppplemented with a saw, etc. You are still thinking in terms of the basic survival requirements, but most likely specializing for the environment in which you will be operating.