My $.02
I think i'd go kickstarter.
Also, I would get the best painter I could find/afford to take your figures to the highest level you can. Find somebody to to do a great job of videoing the accompanying KS Video (maybe add in some stills or period footage of cops and robbers etc).
Maybe do the 20 Mobsters as the "deal", the 8 Hero Mobsters and individual stretch goals, and the Vignettes as unlocked add ons.
It'd be great to have a board game to go with...