I’m new to building AK’s too but I just picked up a nice Romanian kit and have a receiver waiting to be shipped. But for the most part everything is out of stock just like for AR’s.
Not sure how much you know about building but if you buy an 80 pct ak receiver you will have to finish it yourself because like an 80 pct AR lower, no builder will use that 80 because you have to finish it. Others can chime in if I’m wrong about that but I believe I am correct. It’s a legal situation.
The good news is if you send the kit to an established builder they can supply the receiver(for an added fee of course).
On the other hand if you decide to build it yourself, from my research, I do not see an advantage to buying a 100 pct receiver and going through all the transfer mess. Because you are still going to have to do some shop work putting it all together. So may as well do the little extra yourself and you will have an off the books gun.
I guess the best thing for now is research, lot of good info out there and not like yiu can do much anyway. I have an AR i only need one piece to finish. Who knows when the part will come back in stock? But there are other projects and things such as tools that I can work on in the meantime. Just the way it is. Do what you can.