@Simsfan8989 The model on the Currys website is actually more expensive, for the same hardware, than the ones on the Dell website: it's $50 more than the same configuration in an Aurora R9, and $210 more expensive than the R8 I linked (this one). Unless you like the look of the newer Aurora so much better that you're willing to spend over $100 (depending on the exact hardware) just to get the new case, the R8 is still the best option among these.
The other Alienware you linked on the Dell website, the one with the AMD Ryzen processor, is also more expensive for similar performance. For example, the default Ryzen 5 3500X is a bit faster than an Intel i5-9400, maybe a few percentage points depending on the game. But you'd be paying $150 more for it, with all the other hardware (except for the new case) being the same. You could instead pay £90 and upgrade the 9400 to a 9600K and get a significantly faster processor (for gaming) than the 3500X.
The choice between Intel and AMD processors is sometimes complicated. Intel is better for average users, as in, people who don't want to mess around with overclocking and other tweaks or who don't want to stay on top of all the little updates AMD releases to try to improve performance, as opposed to Intel CPUs, which generally work as intended right out of the box. AMD is also usually better for certain non-gaming tasks like video editing, and in synthetic benchmarks (tests made up to measure performance). But if your main activity is gaming, those advantages don't matter.
AMD processors can also be a lot cheaper than Intel, so much so that it's better to buy an AMD even if you don't intend to play with its settings or use it for heavy non-gaming tasks. The idea is that you can get the next better AMD processor for the same price or even cheaper than the Intel you were considering, so even without any overclocking, performance is still going to be better.
This is not the case with the Alienware models I'm looking at. The i5-9600K is as good for gaming as a Ryzen 5 3600 and much better than a 3500X, and it's cheaper too. An i5-9400 is almost equal to a 3500X, and so much cheaper. So within the Alienware models, the choice seems simple: either spend much less and get a 9400, or spend a little more than that and get a 9600K.
Sims 4 won't ever use more power than a 9400 has, even if you're browsing the internet and editing your screenshots while playing. An i3-9100 would also be fine, except you might notice it slowing down in a few years. So if this is an investment for you, and you want to put off getting a new computer, the upgrade to a 9400 is worth the price. The 9600K is borderline worth the price: you won't need if for Sims 4, you probably wouldn't need it for Sims 5 (whenever it shows up), but you might like it for other games.
