From the standpoint of ammo availability, and since you imply that you are interested in compatibility with a single action revolver, I'd suggest that you not go with such early period weapons. Go with something more modern, in other words. You can get '92s in .38 Spl/.357 Mag or .44 Mag, and Single Action revolvers are available for those as well. You'll be able to procure ammo for those much easier and cheaper than the obsolete rounds that the earlier period weapons take.
Regarding the '92 or '94, I'd lean towards the '92 in your case, since you said that you weren't interested in hunting. If you don't need the extra oomph or longer range performance that a rifle caliber gives, then why pay extra for it? The most popular caliber for the '94 is the .30-30. While it is widely available and is quite inexpensive as far as center fire rifle ammo goes, it is still nowhere near as inexpensive, round for round, as pistol caliber ammo such as .38 Spl or .357 Mag.
Have you considered .22lr? There are .22lr lever action rifles as well as single action revolvers, ya' know. If all you are doing is punching holes in paper, then why not?
Regarding the '92 or '94, I'd lean towards the '92 in your case, since you said that you weren't interested in hunting. If you don't need the extra oomph or longer range performance that a rifle caliber gives, then why pay extra for it? The most popular caliber for the '94 is the .30-30. While it is widely available and is quite inexpensive as far as center fire rifle ammo goes, it is still nowhere near as inexpensive, round for round, as pistol caliber ammo such as .38 Spl or .357 Mag.
Have you considered .22lr? There are .22lr lever action rifles as well as single action revolvers, ya' know. If all you are doing is punching holes in paper, then why not?