I think the PKA is 1x magnification but the Belomo PK-A is worth the same as your gun or more so something more economical is a rail adapter like this:
It works fine on my Cyma AKS-74UN, you just gotta undo the two screws on top and then just rotate the rail 180 degrees then screw it back in so it doesn't interfere with the 74U's rear sight.Then attach a red dot of your choice onto the picatinny rail. Holds on tight once adjusted but comes off real easy, faster than most QD thumbscrews so that you can easily put in your stick battery underneath the dust cover and put your adapter back on.
I'll also seen people successfully clamp red dots right onto the rear sight leaf of regular AK rear sights but I'm not sure if this will work on the 74U's different rear sight.
That's my set up and the rail adapter itself has steel components for hard wearing areas so it doesn't seem like it will break soon. I'm very happy with mine but I suppose purists will decry you for "betraying the motherland" or something like that.