If you are from outside Africa, and you intend to take the handgun with you to Africa, then a revolver will be easier to get import approval. Semi-autos invite complications with African officialdom.If you simply intend to carry the gun as a back up in the US, then go for whatever is most natural to you. A full on bear charge isn't the best time to work out how to handle the gun.
If you intend to use the gun as a primary hunting weapon then .454 Casull is a well proven calibre with enough grunt to do the job. Personal experience only, but I would avoid Ruger like the plague. I've had two Ruger Super Redhawks in 454 Casull. Neither should have left the factory. Ruger quality control and dimensional tolerance is non-existent. Issues included a front sight on a 10degree angle, cylinder not square to the axis of the barrel and badly aligned, excessive flash gap, non-concentric forcing cone, barrel groove diameter 3 thou over spec, cylinder throats 4-5 thou over spec. I've seen numerous reports of other people encountering the same issues and sending the gun back to Ruger only to be told that everything is within Ruger's specifications and they won't fix or replace.
Freedom Arms are an order of magnitude better quality, but at a price. Note the FA doesn't have a transfer bar so needs to have an empty chamber under the hammer whilst being carried. However there is another option. Magnum Research BFR revolvers have a great reputation for quality and are at a reasonable price. Choice of Bisley or classic grip etc. Whilst I've never owned one myself, friends who do speak very highly of them. Likewise I've never heard or read of any complaints about their quality.