The glycol/oil cooler type is a good idea. Sized correctly, no thermostat is needed. You can also plumb the cooler in parallel so that you can tune the maximum oil temp via restrictors in the glycol side. It is compact and doesn't need to be in the airstream. An aluminum aftermarket radiator will cover the extra heat load as you will have lots of air flow at speed.
The last thing you want to add to is effective frontal area. You are already trying to push a "brick" at 200mph.
The last thing you want to add to is effective frontal area. You are already trying to push a "brick" at 200mph.