Never been in one of those boats, but if it's like every other boat when you weight it, you need as much weight in those lockers as possible. The 750 or 1100lb bag would work well. Do you have a wakeplate? If so, make sure its 50-75% in the up position (so the nose rises). Put some weight in the bow as well, another 600lbs or so.
If you want the barrel, you need to lengthen the wave. This is done by putting your wakeplate down, or weight in the nose. It's just trial and error from there. Also, faster speeds tend to help for surf style. Skim you want the tall, short wave, so going slower and keeping weight out of the front of the boat helps that. Surf style you want a long not as tall wave, and more speed/bow weight/wakeplate down helps that.
-Mike
2006 Supra Sunsport 20V