Niel, I think a lot of the engineering hardnesses can be avoided with some "assimilation" when it comes to the chassis, you might even be able to tap a market even if people arent in love with the shape :-)
being a fairly tall 5 seater EV, Im guessing overall weight once finished, will be 2000 lbs at a minimum. A tried and true replacement front suspension the hot rodders use might be just the ticket for you:
CUSTOM 1932 FORD IFS FRONT END 32 mustang 2 suspension - eBay (item 290513369341 end time Dec-23-10 17:08:56 PST)
Its a "bolt in affair" and likely to alleviate a whole lot of design headaches.
simalarly, if your going rear drive, a shortened toyota rear on leaf sperings or even a gm might be simple and sturdy (EVs, even lower powered ones can really pack a punch on a diff)
The thing that might be of interest to the market is in you building a "skateboard" GM has been talking about it a while now, where the chassis, batteries, and most of the drive components are in the "bottom 11" of the car. people could build whatever they want in the way of the body (The easy part) Want a pickup, just put on the pickup body, etc..