Budget Build for open world games

What will you be doing with this PC? Be as specific as possible, and include specific games or programs you will be using.

I'd like it to be able to play big open world multiplayer games at 40+fps with the graphics settings on high, stuff like Newworld, Valheim, FF14. Has to handle being in use for long periods of time, like all day, as I'll also be using it for prepping & running online dnd games.

What is your maximum budget before rebates/shipping/taxes? I'd like to keep it under £1000 ($1,360)

When do you plan on building/buying the PC? Note: beyond a week or two from today means any build you receive will be out of date when you want to buy. Sometime within the next month, I don't care about being the most up to date highest spec stuff.

What, exactly, do you need included in the budget? (Tower/OS/monitor/keyboard/mouse/etc) Tower & OS

Which country (and state/province) will you be purchasing the parts in? If you're in US, do you have access to a Microcenter location?

UK

If reusing any parts (including monitor(s)/keyboard/mouse/etc), what parts will you be reusing? Brands and models are appreciated.

Keyboard (very basic usb), mouse (Tecknet usb mouse), monitor (BenQ GW2270)

Will you be overclocking? If yes, are you interested in overclocking right away, or down the line? CPU and/or GPU?

no

Are there any specific features or items you want/need in the build? (ex: SSD, large amount of storage or a RAID setup, CUDA or OpenCL support, etc)

At least 1TB of storage and at least 5 usb slots, 6 would be nice.

What type of network connectivity do you need? (Wired and/or WiFi) If WiFi is needed and you would like to find the fastest match for your wireless router, please list any specifics.

Wired

Do you have any specific case preferences (Size like ITX/microATX/mid-tower/full-tower, styles, colors, window or not, LED lighting, etc), or a particular color theme preference for the components?

Black casing is preferred but it's not that important.

Do you need a copy of Windows included in the budget? If you do need one included, do you have a preference?

Windows 10, I don't mind if that's what tips it over the budget.

Extra info or particulars: Okay so I've never built a PC, I don't know much about them at all and don't really trust myself to actually construct one correctly, so if there're services out there that build it for you that'd be helpful, honestly I'd be happy with a pre-built that met these specs but I couldn't find a subedit for that. Thanks for any help!