May not be the answer you were expecting but I would go with a predator Z shaft. The Z shaft was originally designed to cope with the use of the over sized cueball.
As far as I am concerned it is the stiffest hitting high performance production shaft on the market. Before someone busts my balls over what a performance shaft is... My definition of a performance shaft is that it is radially consistent... It does not have to be low deflection.....
With that in mind you can go to any quality cue maker and have a laminated shaft made with a stiff taper and get what you want for likely less than a predator or OB shaft since the blanks are available from tons of places at a decent price....
As far as I am concerned it is the stiffest hitting high performance production shaft on the market. Before someone busts my balls over what a performance shaft is... My definition of a performance shaft is that it is radially consistent... It does not have to be low deflection.....
With that in mind you can go to any quality cue maker and have a laminated shaft made with a stiff taper and get what you want for likely less than a predator or OB shaft since the blanks are available from tons of places at a decent price....