Kodiak,
I'd also come down on the side of the levergun for your needs. However, I'd ask a question: "Have you ever shot a .45-70 guide gun???
Please do so before you buy. If you don't hunt with hearing protection, then don't use it for your trial shooting ( I am *not* recommending this practice, just pointing out something important :-)
I can't understand why anyone would want a gun that barks so visciously. My brother has a 1895 CB, and even with the 24" bbl it is a beast, but tolerable, which I judge the GG *not* to be. I'd expect that the standard rifle with the 22" bbl to be much more tame than the GG.
Finally, are you recoil sensitive? I shoot the .45-70 with BP-velocity loads, in the 1250-1350 fps range. It is quite pleasant, though a day at the range leaves me a bit sore for nearly a week. My brother shoots 450gr bullets at 1750 fps or better and I cannot *stand* to shoot the thing. One shot is enough for me :-)
So, be sure you want both the recoil and the noise before springing for that beast. Myself, I've decided on a CB in .38-55. All the knockdown that any NA game needs but with tolerable recoil even with maximum loads.
Best of luck with whatever you choose.
Cheers/buffler