My understanding is that you won’t get any benefit of a high refresh monitor if you can’t send enough frames to satisfy the refreshes, it’ll just be additional static images or screen tear.
You could get a 4K screen for your console, but it may murder your graphics card in modern titles/higher settings.
If I were you I’d just get a half-decent bog standard 1080p monitor for around half your budget, for general tasking. You can keep your 120hz monitor for gaming (you won’t notice much difference, if at all, compared to yours ) and your 1070 will be great for some time at that resolution.
A true upgrade for your setup would be a higher resolution g-sync monitor, but the only benefit would be to your gaming rig, not your console, and decent ones are out of your budget. You’d also have to consider scaling, because I believe consoles only do 1080p or 4K.
This is what I would get, a decent workhorse IPS monitor, it fits your preference of 1080p 24” too :
https://www.overclockers.co.uk/dell-p2417h-24-1920x1080-ips-widescreen-led-monitor-mo-08b-de.html
If you want a proper upgrade, the cheapest decent panel I could find was this AOC Agon, it’s IPS, 2560x1440 and 27”, but it’s £650. You’d also have to investigate if it downscales to 1080p well :
https://www.overclockers.co.uk/aoc-...onitor-black-red-mo-046-ao.html#write_comment
The Agon range also has a 4K version for £580. It’ll be ace for ps4pro/XboneX, but your card may really struggle, depending on settings preference :
https://www.overclockers.co.uk/aoc-...descreen-led-monitor-black-red-mo-04c-ao.html
There are cheaper options closer to your budget, but I don’t like TN or the lower end VA panels, so you’d have to discuss those with someone else.
My advice would be to really consider what you want from the monitor, and your setup.
For me monitors generally last longer than any other component, and I don’t mind spending more on them. Ultimately they’re what defines the ceiling of your user experience. But it depends on your budget and your use case, and as I’ve said it sounds like what you need is a second work-horse monitor for general use. Will save you a bunch of cash too
Hope this helps.