I've had maxed pures with the following stats:
1 attack - 99 str - 1 def -85 HP - 1 pray
20 Attack - 99 Str - 1 def - 99 HP - 1 pray
40 attack - 99 str - 1 def - 99 hp - 1 pray/31 pray
50 attack - 99 str - 1 def - 99 hp - 43 pray
60 attack - 99 str - 1 def - 99 hp - 43 pray
60 attack - 99 str - 1 def - 99 hp - 43 pray
75 attack - 99 str - 1 def - 99hp - 43 pray
99 attack - 99 str - 20 def - 99 hp - 43 pray
99 attack - 99 str - 45 def - 99 hp - 52 pray
I had the most fun rune Scim/rune 2h pking in f2p at 40 attack 99 str 1 def BY FAR. 1 attack or 20 attack obby mauler in 2nd, although slayer staff is a MUST for obby maulers. And don't be a noob about getting Rfd gloves, always get them.