Hey mate,
You can take all your IP cams back to the main switch to make it easier to service in future, you will also need to have a POE switch to power the cameras as long as the cameras are POE.
a 1.3 Mega-pix cam will stream 24mb per second so times that by number of cameras to calculate type/size of POE switch to get.
if you wanted to record at D1 res then you would need a recording software that will support Mega-Pix cams, a decent software would cost around $400 AUD plus camera licenses.
good luck.