Unfortunately I can't respond to the art side of it, but would you be interested in a public or private webforum area (or both) for developing this? I help run a website which exists to support amateur game designers, modders, writers and so on. Obviously dw if not, but if anything like that would be useful give me a shout.
Oh, yeah, almost forgot. What we're looking for is somewhere along the line of what "Beneath a steel sky" had in terms of visuals, or if we're talking modern then "Gemini Rue"/"Resonance". But also, even if you're a regular artist, i'm sure we'll work something out