I have some queries out to rewinders, thanks.
The main problem is 4 x the heat, and 1000-odd amps is a bit high.
We need to go to 1000 v plus, with associated air gaps etc, plus extra cooling.
We need a motor designer to lay it out, and see what can be done with any standard parts.
I then need to follow this downstream to motors, transformers, inverters, control etc.
1000 V is not so good for general use- I prefer 500-600 V -not so much risk of explosions, death, instant sunburn, etc.
A hybrid drive off a very powerful V8 might be big enough- I don't know of any common ones. Porsche sports car??