At $700, there's no way you can get a decent i5 gaming build. I admit that i5s are the strongest processor for gaming, but they are expensive. AMD processors are perfectly fine and capable in budget builds. Also, when it comes to AMD, games can actually utilize all the cores because they aren't really 6 physical cores and the per-core performance isn't that strong. The 6300 is only a bit more than the 4300 (~$10 more) and it is definitely worth the extra performance.
Also, Asus boards are very high quality. Gigabyte, Asus, and ASRock are the top three manufacturers in motherboard. MSI is alright, but a lot of their boards has crappy VRM heatsinks which lead to the VRMs overheating. I would definitely go with the top three over MSI. The Asus M5A97 R2.0 is one of the best 970 chipset motherboards and it's on sale (usually around ~$90-95). It's highly rated for its high quality VRM heatsinks which are very efficient and can lead to decent overclocking for a 970 board.