Around April of 2003 National Geographic came out with an issue about
the Sherpa people.  There was a big face of a Sherpa on the cover.

Where (online) can I buy 2 copies of this?

thanxs in advnce,

Sherpaj --

In the past, seeking back issues of National Geographic, we've called
them in Washington, DC.  Of course they sometimes run out of issues. 
Here are the instructions from the National Geographic FAQ:
http://www.nationalgeographic.com/community/faq2.html

There are also bookstores and resellers who handle old copies of the magazine:
http://www.aliensonearth.com/catalog/
http://www.pastpaper.com/

There are a number of resellers beyond those two.  The following
Google search strategy locates them quickly:
"National Geographic" + "back issues"

Finally, I doublechecked the April/May issues of the magazine: the May
issue has a black-and-white photo of Sir Edmund Hillary done by Yousuf
Karsh on the cover.  The issue also includes the article "The
Sherpas," and article by Hillary, and has a map of Mt. Everest.  The
April issue's cover theme is "The Rise of Mammals."

Best regards,

Omnivorous-GA

I believe you may want the May 2003 issue of National Geographic,
which featured an article on the Sherpas:

http://magma.nationalgeographic.com/ngm/0305/feature2/

However, the cover did not have a photograph of a Sherpa. The cover
photo is a black-and-white image of Sir Edmund Hillary, as you can see
by examining the thumbnail image on this page:

http://magma.nationalgeographic.com/ngm/archives.html