Don't forget an edged weapon of some sort.

Most of the classic gunfighters in Western fiction were pretty good with a knife--usually a Bowie Knife or Arkansas toothpick.

Also, in spite of the Hollywood stereotype, few real-life gunfighters were ambidextrous--James Butler "Wild Bill" Hickok, John Henry "Doc" Holliday, Henry McCarty (a/k/a "William ('Billy') Bonney", a/k/a "William ('Billy') Antrim", a/k/a "Billy the Kid"), and John Wesley Hardin are about the only real-life characters from that era who were truly ambidextrous.
Most gunfighters and gunmen (the distinction is intentional--"gun
fighters" were usually law-abiding, or wore a badge; "gun
men" were usually criminals) who carried a second revolver usually fired their first weapon until it was empty, switching to the second only if their opponent was still shooting, or if there was more than one--although the ones who were skillful enough to successfully take on more than one opponent simultaneously were few and far between. Hickok, for example, supposedly did so on at least one occasion, taking out two guys who tried to kill him by coming at him from two different directions--one attacking from the front, the other from directly behind. He killed the man in front of him with the gun in his left hand, and the man attacking from behind by pointing the gun in his right hand over his left shoulder and firing in the direction of the man's footsteps (on a wooden floor, cowboy boots are
noisy).
I say "supposedly" because, while Hickok was admittedly quite skillful, he also had a nasty habit of embellishing his own reputation. (I hesitate to call him a liar, because I never knew him personally.

)
(Incidentally, "Doc" Holliday was also one of the gunfighters who carried a knife regularly, because he often plied his trade--gambling--in areas in which the carrying of firearms was forbidden by town ordinances.)
I also recall reading about an unnamed lawman who wore a veritable ARSENAL of concealed weapons (
eleven, IIRC) --mostly derringers, but he did carry at least one knife. However, to the casual observer, he was unarmed.

Here's a link to a site where I found a Gunslinger character for
SHADOWRUN:
D.J. Faux--Foreigner