outside of the marketing aspect, i'd take amare. if yao were not chinese, basically he's primoz prezec or any other random semi decent center, just 7-5.
nba is moving to a more running gunning league with the new rules. and amare runs like a guard. yao runs like someone chained a cement block to his leg. yao also has barely any jumping ability which is further worsened by the fact that he doesnt even jump quickly (not springy at all) and short arms, and he's not aggressive. thats why at 7-5 he blocks barely any more shots than some small forwards.
yao is a better passer, and has more moves, but physically and potential wise, i think amare wins. amare can always learn moves. yao will never become a fast runner or jumper.