guitarzann:
Another thought you might consider. When I had Shiloh build my .50/90 I had them install a mercury recoil suppression tube in the stock. Since I have no plans to shoot it in competion, the slight weight addition doesn't matter. One of my favorite loads for this rifle is a 650 grain Paul Jones Creedmoor bullet over 110 grains of Goex Fg. The recoil is not in the least objectionable, and in fact feels about like the recoil of my Shiloh .45/90 shooting a 540 grain PJ Creedmoor bullet over 90 grains of Swiss FFg.
I now have on order a Shiloh in .45/110 and have included the installation of a mercury tube in it's stock also.
I shoot for enjoyment and the mercury recoil suppressors insure that I enjoy my shooting.
Just a thought you might want to consider if you get a .45/110 or a .45/120. If you get a Pedersoli (I have a Pedersoli, and I also have a Pedretti, both in .45/70. Believe me, get a Pedersoli! The Pedretti is not all bad, but the difference in quality between the two is remarkable.) you can have any competent gunsmith install a mercury tube for you, or if you are handy, you could do it yourself.
Oh, one other comment. It was mentioned above that the .45/120 cartridge just looks wrong. It's too long for it's diameter. The .45/110 is just a better looking cartridge. But then, that's opinion, and opinions are like noses, everybody's got one. I happen to be of the school of thought that the .45/120 doesn't look right.