There's a lot of mediocre stuff out there. On the cameras since someone will probably need to know... What you want....
Wired or wireless?
If wired, traditional analog video via coax or Ethernet?
Power over Ethernet (or coax), or separate power?
Color or B/W?
IR LED illumination or none?
Any need for pan/tilt/zoom camera or controls?
The questions about the cameras will steer the answers significantly. Then the questions about the recording device start...
Continuous record and rotating FIFO storage or motion detection based recording only?
How much do you want to keep?
"Hollywood squares" style video with multiple cameras on a single screen, or individual camera full resolution recording?
What native resolution and playback resolution desired?
Need server features in the DVR box for transcoding and streaming or just a file server?
Any need for remote mobile device viewing/access?
There's probably others but that's the list I would start with in a spreadsheet before purchasing and only focus on the features I marked as highest priority for me personally.
The PTZ is pretty high on my list for when I finally get around to doing the dream video system. Because that'll mean that the ham radio tower is finally done, and a PTZ camera is definitely going up on it somewhere. But PTZ changes the game on what software and hardware you can use, significantly. Especially if you want web streaming and controls.