Others have fought this battle before. First, to be historically correct, the first widely used centerfire handgun cartridge was the S&W .44 Russian, based on their less than stellar received .44 American. It pre-dates the .45 Colt - and outsold the infamous Colt SAA until near the end of the nineteenth century. In 1907 it was lengthened in case size and made available for BP and smokeless as a 'Special' cartridge, a la the '98 .38 S&W Special. It was lengthened again in 1955 as the .44 Magnum. Any .44 Magnum or Special chambered revolver will chamber and fire the .44 Russian, a historically significant - and neat - cartridge, although you will really have fun finding them - unless you make them yourself.
Latter S&W .45 Colts are made on the similar bore .45 ACP frames & barrels - with longer cylinders, of course. As the .45 ACP is a 21-22kpsi round, vs the .45 Colt's 14kpsi rating, significantly higher performance can be eeked out of a 25/625 in .45 Colt than the usual 'Cowboy' loads. Many, me included, still don't think twice about getting hotter loads in a .45 Auto Rim cartridge than we would load in a .45 Colt. I love my .45 Colt 625 Mountain Guns - and my 4" 629, especially with lighter loads. This is made possible by my basement ammo factory. If I didn't have such, I am afraid I would have to decide if I really wanted to shoot warm-hot .44 Magnums in that 629 all of the time or not.
I do have a compromise of sorts... a 25/625 in .45 ACP & Auto Rim. Now you have a frugal, both in ammo cost and recoil, big bore. You can buy 250 rounds, white box 230gr FMJ 'ball' ammo, for <$90, inc s/t, at Wally World - on a Sunday afternoon. You want to hunt? Thin skinned targets, like deer, can quite likely be had with the 185-250gr HPs that abound in even some SD ammo, the upper end even including that great Speer #4484 250gr Gold Dot. Want to hunt hogs? A 255gr LSWC @ 900+ fps should suffice - and the wild porker won't know it came from a .45 Auto Rim or Colt!
All that said, I have needless duplication - two MGs in .45 Colt and a 625JM in .45 ACP. If I had to seriously downsize, and lose my ammo making capability, I'd keep the ugly full lug .45 ACP/AR 625 long after the .45 Colts and, yes, .44s were long gone. Moonclipped .45 ACP ball ammo is just fun - and not much recoil, either. Buy lots of moonclips - Ranch Products' are ~$30/100 delivered. A 5.56mm metal ammo can will hold 105 loaded moonclips - 630 rounds - try to empty THAT at a range session!
And - if you go the Ruger SA route, recall that some of their recent offerings in .45 Colt are significantly weaker than the former models. Also, the Super Blackhawk is only available in .44 Magnum. Of their .45 Colt-ish DA capable offerings, and I've had both the RH & SRH, the SRH is capable of a far better trigger - and seemed to have fewer problems extracting .45 Colt empties. The RH's drooping ejector rod's star would occasionally skip over a .45 Colt's rim during extraction/ejection, rendering the revolver unserviceable until cleared. As my 4" 625MGs grouped better than the RH & SRH at 25 & 50yd, the Rugers went bye-bye after I got the second MG. I miss the .454 SRH, even if my wrist doesn't. I'll never miss the RH!
I have two 629s - both current production - a 4" & 6" - partial lugs rule! They get mild loads, but if I wanted to hunt - and didn't have reloading equipment - I would get the 6" - and put a set of .500 Magnum Hoque grips on it, for excellent recoil control (Both of my 629s sport them.). And - you can buy real hunting ammo at Wally World - on a Sunday afternoon. You can mail order .44 Magnum 'cowboy' loads - or .44 Specials - or .44 Russians - for play. Be sure to get a proper bore and a chamber brush - and brush carefully 'between meals', always shooting the longer cases first in a shooting session. Choices... how much - and what - do you intend to hunt?
Stainz