Both will work for what you're trying to do. Both have good cable routing options, setup for lots of airflow, and both even use a PWM hub for your fans. The really big difference is in buying fans and which one supports a 5.25" drive bay.
The Nzxt has more case fans preinstalled, but has no 5.25" optical drive bay. The Phanteks would require you to buy more fans to meet the airflow of the Nzxt but does have a 5.25" optical drive.