What's the actual pin length?  If that 5" pin-to-PAP puts the CG close to the midline (for a pro-pin, that's gonna mean a real short pin buffer) then 2-3oz is fine.  Maybe even 4oz, depending on how close the CG ends up to the grip center.

In the end, you gotta keep the ball legal.  The layout you choose will depend, at least partially, on the actual top weight of the ball.  4oz of top weight with the CG close to the PAP ain't gonna work.  2oz is not much of a problem.  The "best" top weight, whatever that means, is the one that lets you keep the ball legal.  If you need a weight hole, a "good" top weight will let you put one in without exceeding the size limits.

SH