WW2 era fighters in modern Close Support-COIN role

That's why I suggest a twin engine multi crew, usually these will have space to devote to their own ECM even if you have to sacrifice some of the load carrying capabilities to do so. For a single engine single seater there's less space (And weight) and anything like that may end up having to carried semi-externally.

That said if you are going up against strictly low tech, or ECM isn't an issue for any reason there's a host of single engine types that would be good choices too.

Corsair, Hellcat and Firefly would probably head the pack off hand for me, I'm not sure but I think they've got better load carrying abilities than the Fw190 ground attack variants but I'm saying that without checking so feel free to correct me.