Welcome to the forum, this is the place to talk about Doubles for sure.

If you have been reading some of the previous posts you know that the 9.3 has a lot of followers and users here. I don't think any of them will say you can't successfully take a Buff with one but it is the very bottom of the legal and power list. Don't buy into the hype that it is as good as a 375 Holland.

That being said, if you can shoot it and want to use it go ahead. It is not a charge stopper but well placed bullets will suffice and buffalo deserve a Double.

As to which 470 to get that is your choice. I would get neither, as I am a fan of the Brit guns and would rather have a used one of those than any of the low priced new rifles available.