Yes indeed there is the option to power these cameras via POE.
How do you connect an IP camera to this DVR?
Firstly you will need to login to the unit , go to System -> Digital -> Channel type, then select the configuaration that supporst IP. An IP camera is then connected to this unit via it's RJ45 (lan port) using a network switch or POE switch.
Request DVR for this Camara & two external camera
Any DVR that supports TVI will be suitable for these cameras such as the Pioneer Quattro.
Do these connect to DVR's via coax cable and do you offer a power supply?
These do come with a power supply. They can be configured to connect to a DVR via a coax cable to view as an analogue camera.
How many IP cameras can be configured onto this unit and does it provide POE?
This can do up to 16 IP cameras depending on the configuration and does not provide POE