Tbh Don't even attempt Mountain Daughter unless you just want the Bear Head to walk around in Non-Combat areas with. You can't complete the Quest because it gives Attack and Prayer XP, thus ruining your Obby Mauler. So if you lose the Bear Head, I don't think you can actually get it back. I, personally, Love Obby Maulers, I also advise you to get 20 attack for Corrupt Statius Warhammer.. It Is Mad. At 75 Strength you would want about 50 Ranged, no more, and definitely not 60+ as this will raise your combat level over 5 levels just for 50 to 60 Ranged. You will be approximately 40 Combat level with 75 Strength and 50 Ranged, this is basically a perfect ratio of Strength:Range - Start Pking here, you will definitely own 70% of other accounts your level if you're decent at swapping to your maul fast and efficiently.
~ As for other quests, I don't believe there are any for an Obby Mauler. Just be sure to put in ALOT of training for 99 Strength if that is your goal.