I suggest reading bbrv's comments here regarding
the "Pegasos 3". Seems they will use the PegII
board but modify it to be compatible specifically
with the 970, so just choose whichever model suits
your needs. The cpu alone doesn't really make a
significant difference for most tasks anyway. But
it's nice to see the choice being offered:

http://www.morphos-news.de/comments.php?lg=en&cpp=1&nid=388&page=28

I will probably be staying with my current model, or
perhaps upgrade to G4 or Peg2/G4.