G27 Gen 4 Lone Wolf Barrel 9mm

'Local shop has a used, great condition G27 G4, with Trijicons and a 9rd mag, and a 13rd mag that I can get for around $450 OTD...I favor the .40 platform, due to its versatility. I will probably get a LW 9mm barrel...My question is this: I know that I need to use 9mm mags, but is an extractor-change needed? Can I expect total reliability with a 9 mm barrel?

Thanks.

G27 Gen 4 Lone Wolf Barrel 9mm