At this time, EAA is the only known source for Witness Caliber conversion kits, and it is my understanding that the Conversion Slide may require fitting.
https://store.eaacorp.com/shop/category/conversion-kits-3I'm not too crazy about the Conversion Kits, as they are almost more expensive than a whole Pistol.
If you want a 9mm Tanfoglio Pistol, try to find either a small frame 9mm Witness or an Tanfoglio/RIA/Armscor MAP1.
When wanting a newer 9mm Tanfoglio Pistol, I went the Armscor route.
However, I did replace the Armscor provided Magazines with Cz75B 17 and 19 round Magazines,
plus I had to replace/tune the Extractor Springs.
Tanfoglio/Armscor/RIA MAP1 FS and MS 9mm Pistols with Hogue Cz75 Finger Groove Gips
and Mec-Gar Cz75B 17 round Magazines