What side do you want to surf on? Due to the prop rotation SANs can be weighted more easily on the side opposite that of a MC, Bu, Tige, etc.
That being said, here is the best configuration I have found to surf on the same side as all the other boat brands:
Full stock ballast on the port side.
Empty and close the ballast tank on the starboard side so it doesn’t fill back up.
500 lb fat sack on top of the port side hard tank filled as much as possible while still allowing the hatch to close.
250 lb fat sac laying on the seat in the rear-port side corner.
Have everyone sit along the port side of the boat. Depending on how many people are in the boat sometimes we add an additional sac along the port side seat.
Typically run at around 8.5-10.5 mph