I myself lean to 5th DnD, 3.5 DnD, Pathfinder, and Exalted but for sake of easiness 5th DnD maybe perhaps 'quickest' to use and implement stuff. The roleplay would be social, explore and intrigue based, and less so combat. As combat can take lots of time so I let players narrate it along with GM/DM input, with possible critical fails or some inside game events (like fall from cliff) decided between player and GM/DM privately and make it part of the narrative.<br/><br/>In regarding the campaign/setting, for intrigue, I would like to use Eberron as it has a bit of magic/steampunk/noir elements into it. Sort run party (in the first campaign very least) a noir influenced detective agency working in Sharn but able go global or requested by higher society across the country solve cases (chasing conspiracy stuff) once fame grows. These are my initial thoughts but not set into stone on it. All depends on other folks what they feel about my suggestion.