I guess the GTX 980 heats up because it recycles air, something more common with small cases and open-air GPU cooling.
When looking at the following picture, it seems like a proper heatsink with two 120mm fans might be possible.
If the space between the PCIe x16 slot and the bottom of the fan bracket is the same or more than the Ncase M1, you could possibly use an Arctic Accelero Xtreme if the length allows it. I have an Xtreme IV with two Noctua NF-F12 PWM fans and a Gelid R290X VRM kit to keep a Radeon 290X cool and it works very well, well below 70°C with minimal noise. But important is that the fans exhaust the heat out of the case, not be setup as an intake.
The included PSU seems OK for basic builds but considering any serious gaming rig, the SFX-L 500W PSUs make more sense with the 120mm fan, 80+ Gold rating (meaning less heat thus quieter) and a higher ceiling (less fan noise at high loads) and modular cables.