The sound of an early Stuka could be approximated via a Junkers Jumo 211 engine, later 87D's used the Danimler Benz 603. For other sounds, your best bet is searching online videos/clip sites for documentaries and propaganda related to "Ju87".
If you have a downloading program, there is a package of documentaries called (Deutch/)German War Files I think...
Might you be wanting the sounds to make an aircraft simulator/game sound 'more real' to your ears?