Consoles don't play more than 1080p when it comes to resolutions (as far as I am aware of...). So there is no need to go for big resolutions. Since most TV have 1080p nowadays, and are cheaper, you can safely go for a TV without worring losing image quality (because, like i said before, consoles Max is 1080p).
One thing you can do is search for IPS monitors that are 27'' and 1080p, check the prices, and then compare to TVs with same size and resolution.
Input lag is not going to affect your experience when it comes to consoles.
Inside the TV departement, you can check for which one has better image quality (colour, brightness, contrast, etc), like you would do in the monitor's department.