I would recommend a Fenix LD01 and a separate whistle, of which you have several choices. My wife and I like the ones from REI. For a little more money, and a nicer appearance, I recently bought something called an IlluninaTi (also AAA) for my wife. She appreciates the bullet proof titanium exterior.

With three light levels powered by a lithium AAA cell, the LD01 is a light I would not hesitate to use to follow a trail on an all night hike. If you value utility, I am afraid you must sacrifice compactness. Oh yes, your budget also goes south, as well. That won't matter once you have used either implement in a significant situation.