First of all, congrats on the new addition to your family.
I use this camera.
https://amcrest.com/amcrest-1080p-poe-video-security-ip-camera-pt-778.html
Recommend any camera in the Amcrest or Dahua range with a built in mic, or Foscam also has audio alarms but with only 3 settings for the threshold so you may find it harder to set the alarm when you have a noise machine playing in the room hence why I prefer the first two brands as they have more control. Get a 2mp camera only as the higher res cameras have more noise (aka snow) with night vision, applies to all camera brands…
Then use this binding.
Then either buy a tablet or a google home hub to use as your screen. The binding can cast the video and audio to any chromecast via the Openhab chromecast binding so you can use a TV but it is more handy to watch a smaller screen whilst watching TV uninterrupted. I have a Samsung tablet as they have a good kids mode in them so when the baby monitor is no longer used the outdated tablet can be used for other tasks or perhaps a habpanel setup.
I really did not like the commercial solutions as they were far higher in price or had tiny low res screens and the camera looks ugly and will not be useful once your child grows up.