The easiest way to get a little better wake is to trim up the outdrive a little. On my dads 21ft Larson a very small ammount of trim up cleans up the wake and makes it a little bigger. Too much though and it becomes very difficult to hold speed. My dad is very anti-ballast but every once in awhile I can convince him to let me through my 400lb V-drive sacs in the floor and the wake does get better with the extra weight.
stick one of those integrated bow sacs in the front and two six hundred pounders in the back. Made my friends wake really nice and now that we added perfect pass it should be a real nice i/o