The only negative I see is that dual core processor being a possible bottleneck. What type of gaming do you actually want to do? You might be able to get a 950 or a 960, but a 970 is like trying to attach a spoiler to a school bus. You could also get an AMD.
If you're suggesting that I get an AMD graphics card, I've looked into that and I've heard/seen that the drivers for them doesn't preform well on Linux.
If the CPU, on this site
here it shows that the i3-6100 preforms better in general compared to a similar priced AMD.
The only thing the AMD has better is the multi-core performance.
However, as for the games I'm gonna play, I'll likely be playing Blockland, Space Engineers, Minecraft (with mods), Planet Explorers, and Kerbal Space Program.
Also to add my budget is 600$ after mail in rebates.