Agree and confirm with all above. I've ticketed six first class QF tickets using CO miles, and in each case first class international is Z. You're fine.

Channa's suggestion of how to pull your locator is a good one, although the Tucson QF rez center will often email you or fax you your QF printed booking, if you cartch them at a good time & are polite. They aren't supposed to do it, but I've never left the USA without my QF printout, yet, in six tickets worth of first class...