My Mauler is currently:
5 attack
85 strength
1 defense
66 hp
54 range
20 mage
46 combat
I would highly recommend getting range, as it is one of the best ways to get your opponent to low health, plus, at 50 and 60, you can use msb and dbow spec respectively.
I would advise against getting any attack until you hit at least 80 strength, at which point you can decide if you would prefer to be a bit more accurate.
My IDEAL stats for an Obby Mauler would be :
1 or 5 attack
99 strength
1 defense
1 or 31 prayer
70 range
70 mage
70 or 75 hp
With the lower options in prayer/hp/attack, you'll be about 50 combat.