qwyendo You don't need the more expensive laptop for Sims 4. An RTX 4050 is more than fast enough for ultra settings even if you add ReShade or some high poly custom content.
Would you like the cheapest good option, or the cheapest good option with an RTX 4060 for some extra power (which isn't necessary but might be nice to have), or would you want to pay more for a particular feature? Let me know, and I'll list some other options to consider. But if you like the £800 option already and don't want to look further, it's a very reasonable purchase.