I have an 06 Outback V w/the gravity one ballast system. I was planning on putting a set of the fly high v drive sacks in the rear lockers. Would I need to add weight to the bow if I put the sacks in the rear or would the factory center ballast be enough to level it out?

Depending on the size of the sacks. We owned an '05 Mobius which is the same hull as your boat and we ran 500lbs on each side. With that much weight in the back you need another 500-600lbs up front. Just lay another sack in the walk thru. Wake will be great.