Advice on my preliminary build for a friend

[trif55]

Gaming PC for a friend - mostly CS:GO and some other Esports titles, some other newer games, nothing AAA from this year at max settings, another friend is still on a laptop so that's a bit of a limiting factor

1080p, 144hz in esports games, lower settings otherwise

£800~

England

https://uk.pcpartpicker.com/list/C7HCy4
That's the base build, the Wifi AX200 seems worth it on the motherboard as an expansion card is about £35 and it leads to a better motherboard with 4x memory slots

the questions I have are

 

GPU: We've picked up a used GTX 1070 for £180 as we can't wait anymore for RTX 3060 etc but that's the long term plan for higher resolution/refresh rate/settings in a couple of years.

 

PSU: bit of a question mark, is that one ok? best bang for your buck? I wish this forum had a list of "current favourite" in each 100watt/£10 bracket 

 

MONITOR!!!: This is a big a question mark, I've got a 27GL83a and am definitely a fan of the 1440p x 144Hz however it's expensive and it taxes my £400 gpu (5700 XT) so blows the budget for now! I'm in two minds between some £60 1080p screen or a 2nd hand one vs the 144Hz because £180 seems a lot for a semi temporary screen what does everyone think?

 

Case: Just need a box to put it in, I don't see the appeal of expensive cases on a tight budget, so was thinking some £24 from Ebuyer: https://www.ebuyer.com/912978-avp-kolus-rgb-mid-tower-black-case-k-181 Ideally I'd like a bit more width, length and 5.25" bays but it seems they're a thing of the past, lol