But for me running and building ak's i would go AK74 at todays prices. Again just from my understanding havent built one so I cant say for sure.
On a side note to builders the bolt on a 74 kit will work with 5.56, 74 mags will work with 5.56 too from my understanding and there are 5.56 barrels for these kits. I hear the bulgy circle 10 mags are the way to go not sure on prices but i do know they have come down in recent years. If I IMHO were going into the platform today I would go 74 based off of ammo cost alone. I got into ak's when the 74's were un heard of and X39 was 60 bucks a case (1000 rounds) for wolf.
Composit mags are just about all you will find for the 74 the surplus mags from what i have heard do very well.