RE: Given these choices?
If the .308 is a Spanish mauser I say stay away from it, they are not designed to handle the higher pressures of modern loads. The 8mm and the Russian is pretty much a handload only option to gain the full potential of the round. Why would you advise against a Yugo SKS, they are some of the finest available. Certainly 10 times better than any Chinese Norinco SKS. I have a yugo 59/66 and would not trade it for anything.