So one gun for all 3 games?
IDPA is the most restrictive on weight as well as overall size of the gun. That rules out the Shadow 2.
The SP-01 Shadow would fit all three. It should make weight and size for IDPA even with the Optic (it’s been years since I shot IDPA so not up on the current equipment rules, but back in the day I shot my SP-01 Shadow in SSP division). For USPSA (IPSC) you would be able to compete with the Aimpoint and extended mags in Carry Optics division, which is ideal for the 9mm. Same setup will serve you well as a pistol for 3-gun (the optic will put you in Open division).
If not intending to shoot IDPA, by all means get the Shadow 2.
I’d buy the gun, then send it to somebody for the extra work you want done: trigger job, mill the slide for the optic, and BUIS. You can buy a mainspring plug that has the lanyard loop for the SP-01 Shadow and Shadow 2 from CZ-USA.
Another option is the P10C or P10F. I sent my P10C to Jagerwerks to mill the slide for a Trijicon RMR then I added BUIS and a better trigger shoe. It’s primarily an EDC gun, but I have been known to shoot USPSA and 3-gun with it, even a couple of night matches with a light on the rail. Not sure if the P10C Optics-ready model comes with a plate for the Aimpoint or if after-market options exist yet.