I wouldnt buy the knife.
I would find a good knife dealer/shop/supplier and buy a gift voucher for roughly the $ amount of the Benchmade model that he liked.
That way he gets the present, a knife and the enjoyment of finding the knife that he wants. You at least dont give a dud gift, and if the knife that is picked is a dud, its not your fault <img src="/images/graemlins/smile.gif" alt="" />