What do you know about G3 and/or AK builds?

I have recently been looking at those "part kits" for multiple battle rifles. I really like the G3/CETME/FAL rifles, however I've read that they are quite difficult to build and receivers are expensive. Does anybody know if you can buy part kits that only require embly? I'm aware that you have to buy the receivers separate and all, I just don't want to have to mess with metal pressing and welding, since I have no experience in metal working. I hear that most AK builds don't require much apart from embly and are (relatively) easy, yet I'm not so sure about it. Any suggestions about what kind of rifles would be practical to build and what tools are needed?