Don't buy anything with that budget. Save some more and get a nice 1440p or 4k monitor.

Okay can you link a nice one of each and ill see... under 300gbp

You have a TV that you can use anyway so I'd just advise you keep using that until you have more money, if possible. GTX 1070 is way overkill for 1080p and that's all you can afford with a £150 budget. You could get a Korean 1440p monitor for between £150 and £200 on eBay. £300 is enough for a 4k monitor, but not a very good one, so 1440p may be your best option. I'll leave some links in a minute, on mobile so it's a pain in the ass, wanted to reply with relevant information first and then give you some links.

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*edit with links*
1440p;
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Cheapest option. Dell U2515H is a nice 1440p monitor, more expensive than this but still within £300. Or, take a look at the QNIX QX2710 and X-Star DP2710, both Korean 1440p monitors on eBay.

4K;
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Cheapest nice IPS 4k panel. Anything smaller than 27" for 4k is a no go, weird scaling, so keep that in mind.

Nice 4k monitor is out of your £300 budget. You can get this 4k monitor within budget;
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But it's TN. I'd personally take one of the nice, IPS 1440p monitors over a 4k TN. GTX 1070 will be great at 1440p too.