@JinxSepia Would you like a gaming laptop, or does that not matter? Decent gaming laptops start around £700, and that can get you hardware that can run Sims 4 on ultra graphics settings, plus 16 GB RAM and a more powerful processor than the ones in the laptops you've linked, both of which you may be glad to have when you're doing school projects. But I guess that depends somewhat on the software you're working with, so let me know if it's not a consideration.
Anyway, for gaming laptops, these are the best options I found while excluding systems with 8 GB RAM or an RTX 2050 (not a great graphics card compared to other options). The last two are the same, just from different stores.
https://www.dell.com/en-uk/shop/gaming-and-games/g15-gaming-laptop/spd/g-series-15-5530-laptop/cn22221
https://www.hp.com/gb-en/shop/product.aspx?id=84T81EA&opt=ABU&sel=NTB
https://www.argos.co.uk/product/3268753?clickPR=plp:8:33
If you'd be fine with a lower-end gaming laptop, this one is £550. Its RTX 2050 might only manage a combination of high and ultra graphics settings, but it's still much faster than any integrated graphics in your price range, and you get a significantly better CPU than the two you found as well, at leat in multi-threaded workloads. Its 8 GB memory could be upgraded to 16 for £20-35, depending on the current configuration, if you're willing to do it yourself.
https://www.argos.co.uk/product/3349809?clickPR=plp:1:33
If you'd prefer not to get a gaming laptop, there are a lot of options in your price range, as I'm sure you've noticed. Let me know whether CPU and memory make any difference to your workloads, although I'd go with 16 GB RAM given your price range. It's not as critical to Sims 4 when a dedicated graphics card is present, since the GPU would have its own VRAM rather than borrowing from main memory, and it's not strictly necessary even with only integrated graphics present. It just gives you a lot more flexibility to multitask while playing or coding.
As far as desktop options are concerned, you wouldn't save any money on a gaming desktop once you factored in the monitor. You would get more powerful hardware for the price though; let me know if you're interested. Non-gaming desktops are usually a bit more expensive than laptops with equivalent components even before the monitor is added in.