what ever car you use it's going to be fast.
think of it like this, Kw = voltage X current, and you have 320 volts and 1000amps, that's 320Kw

minus motor efficiency you'll still get well over 200 kw. even a heavy car will still move along with that much power.
As for range, clearly a small modern car like the cramry of the more aerodynamic commodore, will get better range but with a battery pack that big you'll be able to drive the kingswood over 100km.
as for the motor, id suggest you, get the biggest one you can fit in the car, you've spent the money on the batteries you may as well use them.
I'd suggest use the Kingswood, not because its the smarted choice but because its the funnest, and it's already stripped (i asume that means no motor/gearbox). figure out what size motor you can fit where the gearbox used to be, if you can only fit a 9" motor go dual 9" if you can fit a 11" motor go a 11"HV or a dual 11" motor.
maybe i'm optimistic and someone will shoot me down, but a motor is a motor and a 9" isn't any harder to install (electrically) then two 11". but i think with the batteries out of the way you might as well have some fun with it.
look up some ev dragsters id you haven't already "white zombie" "crazy horse"
and "bi moto BMW"