AMD A-Series processors w/ PCIe 3.0 mobo, AMD FX processor w/ PCIe 2.1/2.0 mobo, OR Intel processor w/ PCIe 3.0 mobo?

I'm looking at upgrading my PC for Fallout 4 and I'm thinking about stepping up to two graphics cards, but I'm on a budget so I tend to go with AMD setups to save money. Problem is there aren't any motherboards that support PCIe 3.0 with the AM3+ processor slot. The only ones out there are for the A-series processors that I don't know much about. Can I build a solid gaming rig with an A-series chip or am I going to have to switch to Intel (which I know less about because they're usually too pricey for me) in order to get a good CPU and PCIe 3? Overclocking is no problem for me as my setup keeps things nice and cool too btw.