Probably a .40 cal SP01.
So I can swap my 9mm or the .40 cal upper onto the decocker lower, shoot both calibers for various gun games, and take the safety lower from my current SP01 and convert it to SA Open Gun type, for the Kadet kit, or either upper.
Should complement my P01 carry gun, SP01 game gun, and Kadet plinker real well.
I would have SA+safety in 9mm and 40 and .22lr, Decocker in 9mm and 40 and .22lr, and a carry gun in 9mm.
Have a FN SLP on its way too, so technically thats the next gun.