ok here is the deal, the attain hubs are one bolt pattern five lug. they are built to work with S13 spindles that is why they are special.
300zx hubs bolt right on to the rear of the car and cost far less from a junkyard than the attain units cost for no real benefit
check
www.raretrick.com
www.takakaira.com
for pricing i believe that
www.jspec.com stocks the GTO brand hubs which are the same thing.
next time do your own research using the search button and google.