Anyone out there ever play one of those instruments where the head can be changed out to make it a penny whistle or piccolo? 
If so, what makes/models have you tried and how did either sound?
One of my home-made plastic whistles has an interchangeable flute “head” (or is it a home-made flute with a whistle head) … sounds much like a whistle (or a flute). It’ll only ever be a compromise, flutes usually have a smaller bore to length ratio than whistles, but I guess it’s a valid starting point, to decide if one wants to progress in one specific direction or another. I’m happy with the way mine sounds as a whistle (low G), my embouchure needs a lot of work before I can say I can “play” it “properly”, as a flute, but I can hack out a single-octave tune with it as a flute and be happy with the result 
… my whistle-playing is a little more advanced (just a little 