Okay, and I'll be sure to ask about headjoints at whatever shop I end up going to.
But for myself, what should I look for when testing a flute/headjoint, other than tone? Maybe ease of playing notes at all octaves?

Here are some suggestions for testing a flute:
http://www.jennifercluff.com/blog/2007/01/testing-new-flute-on-trial.html

Testing headjoints:

http://www.drelinger.com/suggest.htm
http://www.brannenflutes.com/try.html

And an interesting headjoint questionnaire:
http://www.landellflutes.com/-Products/Heads.html