https://i.imgur.com/ATibYUG.png
I think you will like it a lot. I pieced together the same thing, before Ernest started doing that as a package.
But it's definitely the "Easy" button for a defensive shotgun. I kinda lean towards the Aimpoint Micro over the RMR, since you can basically use it with the front sight as a giant ghost ring very effectively. The Micro also tends to get better marks for reliability over the RMR under shotgun recoil.
You may want to add a slightly higher cheek rest on the Magpul stock to get the right height for a fast acquisition of the red dot. It's cheap and easy to do for 16 bucks:
https://magpul.com/firearm-accessori...obal_color=118
Ernest makes great gear, and he and Aimee do an excellent job on customer service. They also hired another really sharp young fellow to do more gunsmithing. This is allowing Ernest to spend more time in his Secret Hidden Laboratory, and also teach more classes. Jonah is doing a awesome work on the trigger jobs. I have one of his 92X pistol packages and it's amazing.