As far as the whistle, check out the VST "The Shephard". I can't believe nobody has mentioned this yet, because not only does it provide an ideal whistle tone sound in such a small VST, but it's freeware.
I don't have enough posts to embed links yet, but just do a simple Google search for: "the shephard" free vst
It should be the very first link that comes up.
Enjoy, and good luck!