Ahmose's primary role is defense centered around Greater Rampart (which offer damage reduction from physical and skill attacks in addition to increasing his block rating but does not provide any defense against magic attacks).

Righteousness is a must as is vitality. Then I would do Nimbleness and Resistance. After that I would do Preciseness/Hawkishness and dexterousness/phantom once available.

Also if you plan to put any 100 frag runes on him in the near future, I would say that Endurance is the most important one to get on him.