I was of pretty much the same mindset as you in this regards.
In my case I was fairly well aware of what rifles the Buffalo hunters used and had access to.
My thinking was that most serious hunters, by the time they had enough experience to order their 2nd rifle, used big rifles in the 14# to 16# class and early on chambered in the Sharps .50 2-1/2" case and later in .45 2-7/8" .
Being that I was already set up for loading and shooting big .45s, that's what I really wanted.
However having already waited for 5 years for my 1st Shiloh (in .45-70) had left me gunshy of wanting to order one that took "longer". (I know, they don't take that long today, but for the HB models, maybe?)
But on a trip that took me across Montana, a stop in Big Timber was "a must".
Stopping by Shiloh I didn't see anything that really caught my eye.
However, down the street, they had a wall of "ready to go" '74 Sharps rifles, and there sat that HB model in "plane Jane" configuration that I could just see as "the tool" a Buffalo Hunter would have wanted.
Trouble was it was a "Big 50". Of course I knew about these, but wait. What about the logistics? Yeah getting the supplies for one of those in the early 1870s might not have been a big deal, when you bought what you wanted for your rifle FROM Sharps. But what about now?!!
It is a jump. And there ARE differences. And "stuff" ISN'T as easy to locate and buy as it is for anything .45 Rimmed caliber and under.
Hmm...I'll have to take that under advisement.
So I go on my trip and I think about seeing that big Sharps. And it keeps eating at me..."Do I, or not?" This keeps eating at me.
Then I figure, "If it's still there when I go back through, I'll make my move."
Heading back towards home I once again pass through Big Timber. I stop and check. There it is. O.k., it's a done deal.
The day before in Miles City I'd seen this.
An original, pretty much the same rifle, but this one in .45 2-7/8"
And here, sitting on the wall I'm looking at this
It's sitting there, saying to me, "Take me home with you!"
So we walked out the door together. The friendly folks at C. Sharps Arms were able to set me up with much of the stuff I needed to switch over to loading .50 cal rimmed cases.
Once at home it took me ~2 months to locate and acquire the rest of what I needed to be able to cast bullets and size them, obtain a supply of .50-90 brass and a few other sundry items.
After all was said and done, it shoots GOOD (doesn't kick too much), is FUN to shoot, gets LOTS of attention when I take it out to shoot, and it's fairly authentic.