I would first get 99 attack.
However, 70 def also means you get Piety. Piety is amazing, you can do 45s with whip and probably a bit more if you wear more expensive str bonus.
But the problem with 70 is, your combat would probably level into the 100s, and at that time a lot of people have good armor; you won't really dish out much K0s with that attack level.