I think we're getting closer to a solidified idea. I'm not tied to the setting I proposed though I still don't quite follow Ty's either. Is the main division between the two the fact that there is a stable world to run to or is there something else? Is it a matter of relatability to characters that come from a world similar to our own? What say you all? Another thing that will impact or decision is the means of arbitration i.e. the system. Now that we know generally what we want it's time to figure out what rules will give it to us. Suggestions?
I get the impression that it's going to be a gritty game, or at least the proposed settings imply that from what I can read.
If we have basically two different settings/planes linked together, a generic system seems to be the obvious option. I'm familiar with GURPS and BRP, and they are both a good fit for a gritty game (and with optional rules, they can be made even more or considerably less
Oh, and there are legal, free and shortened variants of both on the web, in case someone doesn't own the books
Now, I might have misread the intended tone of the game. For a setting without firearms, but with deep-burning passions, the free quickrules of The Riddle of Steel are a good fit - or NEMESIS, if you want to underline the fear and despair. For a pulp story, Spirit of the Century is probably best, but it's long, but I really don't think anyone wants pulp-level super-characters.
Well, these are my suggestions - there are lots of them, but it will impact the game significantly, so I decided to give you more choices...
Maybe we/you should start discussing not only the setting, but what genre you want to play and how you imagine the tone of the game (these can be rather different things)?