Regarding quality and reliability, a wired 4K system is likely the better option. However, wireless models can certainly get the job done. The main thing to consider here is where you intend to place your cameras and how far away from the central hub each camera will be.
Wireless systems do not tend to work too well outside of a specified area and because of this are likely more suited to indoor situations. For most outdoor surveillance setups, wired systems are the most appropriate.