oh. and cpu will be amd fx 6300 probably at around 4.5ghz
If you want to be gaming, you'd be much better off with an i5 3570K. You can get an 212 EVO cooler ($20) and overclock it to 4.2Ghz easily. It will outperform that CPU in games -- even non-overclocked.
In the next 5 years there "may" not even be PCs anymore.
5 Years in PC world can be HUGE, or a simple upgrade.
If you consider all thats going on (intel going off the motherboard sector, Intel aiming for 5nm processors, etc), impossible to know.
Personally, when ill get my new PC, ill go for 16 Gb "just in case".
But for now, 8 gb is enought for everything (in most cases, 4gb is as well).