I have the factory threaded barrel in mine, purchased from CGW. It dropped in, and the gun remains amazingly accurate.
A SilencerCo Octane, Osprey, and Hybrid, and Omega9K all work very well on it. I will be buying a dead air ghost for my dedicated handgun suppressor, because I like the modular length and ill get a good price. Otherwise I would get the rugged obsidian, same reasons.
Silencers are totally worth it, trust me. Subs and a little water in the can and it's amazing how little noise they make.