Re: AK 47 red dot
Count yourself lucky that these are good times for AK accessories, that is to say that there are now more colors of lipstick to put on pigs
My prefered set up is a mini red dot such as the Trij RMR, Insight MRDS, Docter or Burris. Those are arranged in order of cost from high to low btw.
Second option would be a Aimpoint T-1, Vortex SPARC or Primary Arms.
Lastly would be the Aimpoint style 30mm tubes.
For mounts you have the Midwest railed handguard, Midwest/US PALM dedicated handguard top mounts and LAV's prefered Ultimak rail.
If you decide on a mini red dot I suggest the Attero mount, I also owned the MI mini mount but didnt think too much of it compared to the Attero although the machine work is much better the Attero get the not for ruggedness.
Well that should get you started lol, after trying many combos I ended up with the Attero and an MRD
Also stock with 3.5-4 MOA dots some optics are 7 MOA or larger which is fine to about 100yds but IMO too big beyond that range.