As far as setting, plot and characters are concerned, I will leave it in your hands. You're more than capable with it. I do think, however, that it should be an original IP, original setting. It doesn't have to be something entirely new, just something original with a certain degree of complexity. (Plus you get to milk the IP forever afterwards, since it's going to be entirely yours.)
As far as gameplay is concerned, I don't mind whatever combat system it has as long as it's reasonably balance, you can't gimp a character without some effort and, for the love of god, not twitch-based. I do hope, however, that it has meaningful choices. Something along the lines of Alpha Protocol is on the right track in that regard, plus---give us a greater FEEL of the weight behind our decisions. Not morality hammering, no, just a weight of what it means in respect to the setting/plot.
On cosmetics, i.e. graphics/voices/etc. : I really don't mind either way, but for practicality's sake I think a good old 2D isometric look would be best. You're looking to fund this at least partially on Kickstarter, so the cheaper the better---and I think it's been proven that you have a fanbase with a great love for 2D isometric, which is something that goes very well with your experiences as well. The same goes for voices. While voice can help improve immersion, I don't think they honestly improve immersion that much when everyone says the same flavor text over and over, and I'd rather like a game world that is truly immersive instead of one that feels like it. Furthermore, they're costly, and that resource could be better spent elsewhere.
I'll be happy to fund anything you make, since I've been dreaming about this for a long, long time. Please make it a good game. (I'm doing everything I can to keep this post from turning into incoherent flailing, so please excuse me if I sound strange in spots.)
EDIT : P.S. Somebody on Twitter said 'spiritual sequel to AP, with more focus on being a manipulative jerk.' While it doesn't have to be a spiritual sequel, I feel that the second part has merit. More opportunities to manipulate the world without the act automatically translating into being evil, please.