After listening to your goals of having less fiddly things like doors and interiors to do but still having a go at exterior design I was thinking about the Porsche 996 chassis. They can still be had relatively cheap (for a Porsche) and the IMS failure might be a good candidate. Also they made AWD versions in the Carerra 4 and Turbos so you could either adapt the physical driveline, or possibly put a Tesla drive unit up front for AWD. Lastly, there are limitless suspension and upgrade parts for the chassis as well as tons of bodykits that could serve as a base for your project.