While I can fully understand the need for something that can fly low-and-slow to bring the rain to the terrorists, a slow aircraft is even easier to hit with machinegun fire than a fast one. Something that small can only carry so much armor before it becomes too heavy to fly, and it has to be able to get out of range quickly when it needs to.
To be honest, re-creating one of the old WWII-era fighters might have been a better choice. Some of those had ridiculously low stall speeds, and much beefier airframes. They also carried engines that could hit nearly 1000hp under emergency power. Something like the old P-40 or P-47, with modern avionics, would fit the bill nicely (and ya gotta love the sound those old fighter engines made).
Correction: not nearly 1000hp, nearly 3000hp (though those had some teething problems).
I’d say do an updated p-51.