Turmoil or piety, or 52 prayer...

I am a nearly maxed zerker pure, level 98 combat. The only thing I am needing is turmoil. However I dont have enough money right now. I have been making a decent profit rushing and whip to claws pking and I have enough money for 70 easily. Would this help, having 70 prayer for pking? I am not sure how much it would raise my level, but I am 52 now so I am guessing I would be 100 (2 combat level gain) or so... It would raise my max hit with claws by about 25 points (50 with spec). What do you guys think?

Also, how hard are the quests to get piety?

 

You are aware that you need 70 defence in order to use piety right?

 

Doh! I feel stupid, not planning on 70 defence anytime soon. Turmoil it is!

If anyone could explain how the Initial boost and final boost work for turmoil that would be great. For example, if I am claw rushing, will I receive the final boost as soon as I click "attack-target name", or do I receive this boost after my first attack lands on them?

 

After the first spec.