I have a Vepr AK in 762x39, it is my favorite, and two Arsenal milled receiver AK's,, with a scope and quality ammo,,like Lapua,,you can get 2 MOA at 100 yards. These are expensive AK's at $800 to over a grand on Gunbroker even back when I bought them. However you will have just as much fun with a $400 AK.
I would probably go with 762x39,,,I do not like corrosive ammo and do not clean my guns every time I use them,,and prefer not to worry about them,,however if you could get non corrosive ammo for the AK74 I would buy one. The Saiga AK's from K-VAR seem like the best deal to me.