With 5.45 there used to only be the choice of Russian surplus corrosive 7N6 which is the cheapest you're going to get or Silver Bear (which I'm not the biggest fan of). Now Golden Tiger makes it, which is great.
http://www.sgammo.com/product/golden...w-production-a Same price as 7.62 from SGammo, but hey it's available.
The only major thing that sucks about the AK74, is finding good mags.