Hi Eli
It is a very unique problem, most homes across the globe can not support this amount of Amperage. You would likely be much better off moving from single phase high current to three phase at a much lower current. There is already a 3 Phase 63A standard which could get you up to 45kw.
You will need custom firmware and hardware on both the station side and vehicle onboard charger.
There are no vehicles that have onboard chargers that can handle this amount of AC power and convert it to DC for the batteries. You will need to develop a monster onboard charger for this.
You will likely need a custom socket and custom charge handle as well. The wire size to handle 200A is huge. Going to 3 Phase would help and switching to DC at battery voltage would help too.
Missing the point? "I want to plug in a vehicle that can pull 200amps ac" . The point was certainly not clear.
For non-EV use just use the connector. No need for any pilot signaling. An appliance or tiny house would not be able to control load like a DC onboard charger on an EV can.
J3400 NACS cables and connectors are not cheaper than NEMA 14-50 RV plugs. The OpenEVSE product uses both. Our NEMA 14-50 "RV" Input cords cost less than $50 to manufacture and 3400 NACS cost more than $150.
J3400 NACS cables have a thermal sensor option. That can be used to push the limits on wire ampacity. That said the goals in this post are unclear, and seem unwise.
Eli Protica