P-226 Legion 9mm Slide Kit

There are 9mm slides for the Legions, typically you have to get the one with the optic. Direct from Sig
There are conversion barrels from barsto
The 9mm mags fit fine.

Slides that will convert your gun that Sig makes (you need to also buy a barrel and correct recoil spring):

thank you @KenBry

Here’s an entire slide assembley it’s a Mk25 but will work fine on the Legion.