From my readings there have been claims and denials
regarding the existence of JSF variants. Basically it seems the USAF
will get the most capable version, with the export variant not being as
capable.
I found this

http://www.newsaustralia.com/28-June..._next_best.htm

I wonder how accurate this article is because it says that the RAAF will
get about 60 - whereas most commentary on this topic has until even
recently suggested a number of 100 as F-111 and F-18 replacements.
Personally I have some reservations regarding the retirement of the
F-111 fleet. Carlo Kopp has been most vocal in his disagreement.

http://afr.com/articles/2004/02/11/1076388428882.html

http://www.sci.fi/~fta/aviat-6b.htm

rb