So I basically want to know if the 8350 is a lot better than 4130. The only real difference is that the 8350 is a 8-core and 4130 is a quad, so would it be helpful to have 8? Also will quad be enough for gaming in the future or will you need a 6-8 core soon?
The price doesn't really matter but the 4130 is nearly half price, so if there is no real difference and IF quad will be enough for a couple of years, I would rather pick the 4130 . I doubt the 0.2ghz difference really matters, as I'm pretty sure 3,8-4ghz is enough.
I doubt games will need 8 cores anytime soon. Like the i7 the 8 core AMD has Hyperthreading, something which games don't utilize, but professional graphic applications do. So if you're just doing some gaming, you're not likely to see any difference. It's a similar story to the i5 and i7.
Personally, I have an i5, but if I were you then I'd get the best of both worlds and go for the 6 core FX 6100, I don't think it's much more. This way you'll have a high end CPU, but also money saved to spend on other parts
The rumor mill right now claims that the next consoles will have ~8 core CPUs so it wouldn't be crazy to expect future games to use 4 or more cores. Plus you will be happy to have the extra headroom in case you plan to do recording, streaming or rendering in the future.