Well, in Deadlands (Hell on Earth), Junkyard is the only true city left. As a survivor of the apocalypse...err...make that the second, zombier, apocalypse, there was a lot of top notch loot to be had (it's also where a good chunk of the traders stopped in and where the apocalyptic mad scientists built their mojo machines of doom).
For the warzone suggestions, just think about the kind of troops that are going to be deployed in those engagements. High grade armor, weapons, vehicles, and ammunition galore.
Thinking more on it, how would this sound, dropping into a warzone that has just been subjected to a terrorist attack (nuclear, chem agent, etc.). Three current parties duking it out in the city (terrorists, army A, and army B). To really add a bad day in, the terrorists discover how to summon mass shedim spirits in to possess the dead.
Why are the runners there? To extract a target from a high security prison in the center of the city that is currently under complete lockdown akin to Fort Knox. Unfortunately, the offer was made in an unorthodox way (over live streaming news) so there's sure to be other runners trying to swoop in on the golden goose as well, but on the plus side, the target offered a billion nuyen to be freed (and his background checks, just hope he pays). Of course, with all the AAA guns in the area, the runners have to drop in outside the city and work their way in just to get to the prison. Getting out is going to be another bitch and a half.
TLDR: Smash together an active warzone, S.W.A.T., and the hecticness of 24, stir slightly, and play gently. Repeat attempts as necessary (afterall, it makes sense for multiple attempts to be made).