I just want to double check I am buying the correct mounting:

I have the DM/ASR Tube and 556 ASR MAAD Muzzle Brake.

I'm looking at pictures on DM's website and on the SilencerCo website. DM's website looks like the Omega 300/Hybrid 46 in the picture but I'm not sure if that's the mount in the 1st picture will fit DMs tube and 556 brake.  Also the 2nd picture doesn't look like the ASR MAAD mount I see on silencerco's website, but it's labeled as MAAD ASR on gun broker? I that the same one? I'm very confused.

The first two pictures are the MAAD module. It is not the ASR that you need.

The mount that fits DM's ASR tube looks like your third picture. My ASR mount that fits that tube is SiCo PN AC824 and they labelled the bag HBB ASR Mount.  My understanding is the Harvester Big Bore, OMEGA 300, and Hybrid 46 all take the same ASR locking collar back end.