www.benstoegerproshop.com is a good one stop shop for pretty much anything competition shooting related. I usually recommend their full BOSS rig for a belt/holster combo. I run 17rd mecgars for mags with the Henning pro basepads. Springs from CZC or Cajun are good. I run the Cajun 11.5#hammer spring, 11# recoil, and the extended firing pin w/ spring. The stock grips are pretty garbage imo. LOK or Henning are both nice. There are other optional things you can throw money at, but expect diminishing returns very quickly. The consensus of the GMs around me that use a Shadow 2 for what it "needs" are hammer spring, recoil spring, and decent grips. Sent from my Pixel 3 XL using Tapatalk