Hi
First, it needs to be mentioned that for dual Kinect 2 system you'll need 2 PCs for recording, each for a single Kinect 2.
Actually, Kinect 2 differs not that much from its predecessor: having a wider FOV, better accuracy, less noise, and the same range and FPS.
Two Kinects can capture a wide range of motions (in a limited space), but are only capable of 30fps.
So if you want some really quick motions, then 60fps provided by PS Eye may be a big plus. Also PS Eyes give you a much bigger capture space suitable for distant motions.
For connecting PS Eyes you'll need USB 2.0 repeaters (active extension cables) like these ones:
TrendNET,
MonopriceYou can also record from multiple PCs to simplify connections.