Generally speaking, 8GB of RAM is the 'sweet spot' for gaming rigs. It's enough.
As for the GPU vs resolution, yes, that is DEFINITELY overkill. The 970 is a great card, even at resolutions higher than 1920x1080. Rendering at 1366x768 will be effortless for that card. I have to recommend you buy at least a 1080p monitor to get the most out of your rig.
As for overkill being good or bad... I have to say it could be either. If you don't do heavy gaming then you don't need a powerful gaming PC - in that case, overkill would be bad as you would be wasting money.
On the other hand, if you do a lot of heavy gaming and want to build a future-proof system that can run the latest games with ease, then overkill would probably be good.
By the...