I guess guns are pretty much Fallout 1 stuff, some from Fallout 2.
As for the characters-
Dr. Reynolds is a tall, thin, Anthony Edwards type science type. A bit bumbly and not to wise despite his knowledge
Jasmin- Angela Basset in Strange Days, except buffer and a bit of a lesbian and evil thing.
Deeds- Kind of a midsized bulldog of a man. Think of some of the roughnecks in Starship Troopers.
Dr. Maddy Stowe- Madelaine Stowe from the Last of the Mohicans ro 12 Monkeys. Kind of a tragic character, trapped in her fate and not to happy about it. Smart and looking for a way out.
Kilrick- never wanted to give him much definition, background, etc, in order to maximize the feel of the first person tense. But I have always thought of him of something of a cross between Gabriel Byrne in Miller's Crossing, Sam Spade from the Maltese Falcon and Mickey Rourke, from his earlier films (like Angel Heart)- an anti-hero with unclear motivations and morals.
The other characters- up to you all.
Location- this is upstate New York/ Conn./ NE, a few hundred miles due North of Manhattan. The river is the Hudson, which is a fairly old river surrounded by hills that tends to curve. The towns nearby are pretty old, brick, industrial. Rough ground really, with the vegetation recently coming back. SOme of the bridges are out, rivers are hard to pass except for ferries. Different factions are fighting for control so some areas are battle field no-man's land.