For me a traditional Toyota
For me a traditional Toyota style hybrid synergy drive wouldn't work. What I think would work is a setup on a 4WD pickup where an electric motor off the transfer case can power the front wheels when the truck engine is in rear wheel drive mode. The motor wouldn't have to move an unloaded truck faster than 25-35 mph and anticipated use would be when stuck in traffic, maneuvering into a parking spot, pulling out of the garage, that sort of thing. When the truck is towing or in 4WD mode, the motor could stay out of the way. Another nice thing about having hybrid batteries in a pickup truck, would be all the uses for the big battery powering an inverter (big enough to run a circular saw at a temporary job site, or keep the home furnace running during a power outage) while the truck is parked.
Make the engine that BMW N57S inline 6 diesel and the transmission the Tremec TR-9007 DCT and it could be a nice truck.