General guidelines for reliable exchange of asian language files?

Our U.S.-based office prints packaging for asian colleagues. Their InDesign, Illustrator, and PDF files contain asian character sets. Often, the supplied fonts and embedded fonts are unfamiliar and unavailable in the U.S.. I'm concerned that font substitution or other text changes can occur nonetheless. I don't want to recommend that they covert type to outlines.

Are there any general guidelines or best practices that will ensure we-- and our print suppliers-- accurately reproduce what our asian designers intended? Can you recommend some high quality fonts for traditional and simplified Chinese languages?