Help With PS4 Pro.

Hi, I'm currently playing regular PS4 on a 40" TV and plan to move the system into my room. Im planning to get a monitor for the PS4, but then I can exchange it for a Pro variant. I have two questions:

1) Is 4K on a monitor equal to 1080p on a Big TV? If no, then can someone suggest a good monitor that is 4K compliant with the console?

2) Users who own a PS4 Pro(or upgraded to it) : is the difference noticeable? Will my current setup with a 1080p monitor do me good?

Thanks.