Long range pistol shooting is my favorite thing in the shooting sports....
I guess it's that whole "using an abject so singularly unsuited to the task" Twain thing...
Anyway there are a billion options.
For a G_R_E_A_T inexpensive oprion, a CZ-52 in 7.62X25 is an OUTSTANDING long-range pistol (At exactly the distances you are talking) because of it's velocity.
The 9MM is FAR superior to the .45 at legnthend ranges, due to it's higher velocity...
A +P+ Hirth or 124 Gr. NATO out of say a Glock 17 is totally capable of hitting a man sized target at 100, I do it all the time, and have witneses to prove it.
The 10MM is one of the best, due to it's velocity, and frontal area which carries a healthy kill potential.
A Glock 20 with an extended 6" BBL is the END-
You must remember that the #1 thing you need in long range pistol shooting is the requsite skill to do it; there is no magical gun that will allow a hack to tap out to 100 with [red]any[/red] handgun.-