I'd do some reading on optics, etc as well. Been a while since I researched this stuff myself in depth when selecting my PA dot for my 15-22, but you will want to understand size of dot (usually expressed in x MOA) and how that impacts the type of shooting you plan to do, etc.
Also, if you have vision issues, certain types of optics can interact with those conditions in certain ways ( https://www.thefirearmblog.com/blog/2016/07/06/the-more-you-know-astigmatism/ )
Then depending on the application of the optic, and using iron sights as well, there is the whole aspect of co-witness, etc.
I'd do some reading on optics before getting too crazy if I were you, especially since you don't have a good handle on mounts, rails, etc currently.
Both MkIVs are drilled and tapped, you just need the rail. The Buckmark should be the same.
The 22As should have a rail integrated already.
I'm excited to hear what you think of the red dot