I have a self imposed limit of 100 yds. when using BP cartrdige rifle on game. I just can't judge distance beyond that, and being from the east it is hard for me to show up in wyoming and judge distance where there are no trees every 50 ft for perspective. Since I carry a traditional rifle with a traditional cartridge I refuse to carry a range finder. Even if I did, i wouldn't shoot beyond 150 yds as the drop is just to great for an occasional shooter like myself to use iron sights on.
If you should also limit yourself to such ranges, I can't see much difference in the killing power of the .45's. They are all effective. But there will be a difference in ease of use. Once you get over 80 gr. of black powder, it seems that the degree of difficulty goes up, or at least care in loading. It took me a full year to figure out my .45-110, case stretching and inconsistant patterns were a problem. Shoving pride aside, I finally went on the Shiloh board and begged for help. Problem got fixed. But I have found that with my .45-70 (sharps or springfield) I could be pretty careless in the loading and case prep department and still get good results at 100 or 200 yds - the distances I practice at. Recoil is not an issue amongst any in my opinion.
I have never shot the high walls or rolling blocks. But if your interest is in sharps I can recommend the Pedersoli, mine is in .45-70 and is a great shooter. From what I understand it is the only Italian that is competitive with the American guns. Having said that I haven't shot mine in years.
That brings me to the final point. If you want a Sharps type gun MAKE SURE YOU GET THE ONE YOU REALLY WANT, did I say that loud enough. If you don't you will end up with two guns, the one you always wanted and the one you could afford, the latter will sit in the safe forever (like mine does). If you are going to dump $1000 into a Pedersoli, then wait until you put together another $700 and get the Shiloh, there is that much difference in quality - honest. I have two shilohs and I will starve before they go on the auction block.
My favorite caliber for hunting? The .50-70 in my 28 inch heavy barrel hartford. It like the .45-70 is easy to load (take that to mean sloppy technique and still forgiving) and the difference in bullet drop is neglegible. I just like the history of the cartridge.
Anyway all these stressfull decisions are a treat to worry about. Have fun.