You could get you a box call and have the calls pretty well down within a short period of time.
I am not trying to be a smart alec, but hunt them wherever they are. Just get out there and find them!
I would recommend a #6 lead shell if you are going to use your modified choke. There is no need to step up to heavier than lead loads as you will not reach their potential with that choke, and you will have plenty of killing power as far as your pattern will allow.