If you want a good solid repeater you can't go wrong with a Marlin 1895. The Win 1886's will probably cost you a bundle or Win 1885s the same. For single shots a great one is the Ruger #1, Browning 78 or the newer 1885. The Win 1885s will cost you more. The 1873 springfields will be either reasonable or expensive depending on the vintage or documented history.
I love the .45-70. Its a great old hard hitting cartridge. And ammo isn't too costly for it. So if you don't plan on shooting too much you will be OK. Besides the .45-70 isn't a 'plinker' anyway. Now if you do reload and get one of the more modern rifles you can really stoke it up. Factory loads are mild so they don'[t blow up the old springfields.