after browsing and reading for quite a while on both, I decided to go the AR route. I love the look of the AK. They are made to handle abuse, and last forever. On the other hand, the AR has far more options and is very easy to work on. Also, if you buy an AK from an imported parts kit, it must conform to the 922r guidelines.(a maximum of 10 out of 16 specific imported parts). I ended up choosing the AR based on a couple reasons. I can reload the ammo much easier for the .223 than the 7.62. The majority of 7.62 that i see is steel or aluminum case, and the brass is just as expensive as the .223, which defeats the aspect of ammo being cheaper (for me at least). I have more friends with know-how on AR's and nobody i know deals with AKs. I decided i would rather do long range shooting (which the AR is better suited for) than the medium to close range that the AK is designed for. Im also interested in shooting 300 aac Blackout, which is based off a .223 round, so the only part i would need is a barrel. I will probably end up just getting a different upper, so i can just swap them out on the fly though. Also, a .22lr conversion kit can be had for right around 200 bones. So if the ammo prices return to normal, it will be a lot cheaper to do the majority of my plinking with that. Im not familiar with the 5.45x39 round, so i cant speak much to that. Ill have to look into it though... I probably will end up owning an AK in the not too distant future, but I am happy with my choice for now. I ended up buying parts and assembling my AR with the help of a friend. Good Luck, and if you do end up building an AK, keep us updated! I would love to see how it turns out.
heres a couple pics of my AR...