Sorry if this isn't the right forum to post.
What kind of monitor should I get for CCTV viewing?

Any computer monitor with SVGA input will do.

any monitor will do

get a low power consumption monitor if you want to save electricity

or a big sized screen if you need to view many camera feeds in one time

most DVR nowadays comes with VGA port... any LCD monitor will do...

A real heavy duty CCTV monitor will cost thousands.

The guy suggest me not to get too big sized monitor for just 4 camera feeds. I think somewhere 17" is enough?

get a 4:3 aspect ratio monitor

that is the non-wide version so you won't get skewed images

which size is depending on your budget and space to place the monitor

Whats the cheapest price I could get? Anything that fits for budget maybe around 2xx ?

you can check the trading forum for that

u can get cheaper price if u get a used monitor

You can order from Lazada... RM250~RM300 for AOC monitor