Apparently you've overlooked them Ashley, Yesasia does sell overseas versions of her DVDs. They are Region 3, and made by Avex in Hong Kong. Here are some links to overseas DVDs:
Tsuki Ni Shizumu DVD
http://us.yesasia.com/en/PrdDept.asp...raoke&did=161&
DOME TOUR 2001 A DVD
http://us.yesasia.com/en/PrdDept.asp...text=&did=161&
concert tour 2000 A part 2
http://us.yesasia.com/en/PrdDept.asp...text=&did=161&
And there of course, are more.
And CDJapan only sells original Japan versions because they are located in Japan and overseas versions are illegal.