I have to agree with Daniel here that bone probably isn't the best choice for a hard use knife. Especially in a survival situation type knife. If you want to keep in tha natural materials then a good solid harwood would work fine, but for a real hardcore knife I would like some type of synthetic better. Any natural material will sucmb to the elements and use over time, but some of the synthetics such as G10 or micarta could probably last forever. This is especially true in a situation where the knife might be getting used in wet conditions, and you won't have a chance to dry and clean it off after each use. Of course the downside is that the look isn't really up there with a nice bone or wood.
I think you really need to decide if the knife will get used and abused, or if you just want a nice looking traditional bowie style knife. I am sure many makers make fine knives with a bone handle that could be used, just not abused.