Although the P-40 is considered inferior to the Bf 109 and the Fw 190, it is still my favorite WW2 fighter. It was a real workhorse, could sustain a lot of damage, and is said that over 200 Allied fighter pilots from 7 nations became aces flying it.
I really enjoy flying the Flight Replicas version of the P-40. The model seems accurate, the textures are good, and the cockpit is detailed and functional.
This does work with P3Dv4 (I asked the developer. He mentioned the gun site doesn't work properly, but I didn't notice a problem with it. I normally fly with it off anyway).
I should mention that this version isn't quite as detailed or has as many extras as the A2A P-40, which costs significantly more. However, it's still a very good aircraft.