Is extra fancy durum the same as 00 Flour?
No, Durum flour is made from durum wheat, 00 flour is an Italian designation for a fairly soft wheat flour used for making pizza crusts.
King Arthur's sells versions of both:
If you need to substitute, you can use All Purpose Unbleached Flour to approximate 00 flour. For Fancy Durum Flour I substitute Bob's Red Mills Semolina Flour which my local grocery store carries in the health food section.
These are good questions though. I added something about both to the Fresh Loaf Handbook.