Linus overclocks every GPU he gets. I'm 100% positive what happened there was he got a near-perfect 270, and a poor 270x lol The 270 is 'binned' lower, meaning 95% of the time it will be, although the same type of chip, of a lower quality, meaning lower overclocking headroom, life-span, etc. The 270x also allows more power draw, which helps overclocking ability as well.
You may get the same results as him, but the 270x will be better 99% of the time.
Overclocking is possible, but I wouldn't overclock much on the 970 series chipset, be it ASUS, MSI, Gigabyte, whoever.
MSI 970 boards are junk. The VRM's on them tend to go out. The Asus one the OP suggested is OK, a Gigabyte 970a-ud3p is best for 970, though. The combo you listed is decent, OP. I would try to get the gigabyte board I mentioned and an R9 270x if possible.
Thanks guy, now iv considered getting the 270x, how would a sapphire one compare to MSI? In my country a sapphire r9 270x dual X cost 30-40$ cheaper than the MSI twin frozr
For OC purposes what mobo would you prefer? A gigabyte 990FXA UD3 would work if i stretch my budget? (rev 4 is better right?)