@abigailevelynn__ When I say overkill, I mean that a computer or one of its components has more power than Sims 4 needs or can even reasonably use. So while someone might want to buy, say, an RTX 2070 or 3060 ti for other games, those cards would be wasted on Sims 4. It's not a bad thing, just a question of rapidly diminishing returns above a certain point.
Mods mostly tax the processor, not the graphics card, although a few mods do come with visual components that require some extra graphics processing. (Think of ones that add skin details or the like.) All the processors in the computers I linked should be able to handle whatever mods you want to use, and a 1660 of any flavor should also be completely fine.
However, the game engine itself will get bogged down from time to time no matter how fast your hardware is. This is exacerbated by mods, which increase the amount of data to be processed. There is unfortunately no good way to get around this; it's just how the game is built. As an example, with Eco Lifestyle NAP voting enabled, when each voting session closes, the game will need to tabulate the votes and apply the relevant info to all affected sims. You might well notice some lag or a short freeze at that time, with or without mods. If you do have mods though, and some of them are adding to the overall load on the game engine at that time, the lag or freeze will be more pronounced.
In theory, the stronger your processor, the more quickly issues like this get resolved. In practice, the game engine itself is the limiting factor to some extent, and there's only so much fast hardware can do. Having a processor with a higher clock speed (more calculations per second) will help, but more processor cores won't: Sims 4 can only use four cores at a time. (If you're doing other tasks while playing, the other cores can handle those and free up resources for the game, but unless the workload is particularly heavy, six CPU cores is more than enough.)
All this is to say that you can spend more money on better components, but you're looking at diminishing returns. I would say a 1660 is worth the extra cost above a 1650, and a 2060 might be worth an extra $100 but maybe not $200. For processors, an i5-10600KF is almost exactly as fast as an i7-10700 until you're actually using all eight of the latter's cores, so spending an extra $150 on a 10700 is a waste as far as Sims 4 goes. Even the i5-10400 is only about 8% slower in gaming if you don't intend to manually overclock, and a Ryzen 5 3600 about 3% slower than that, so you may not notice any practical difference among the options.
RAM and storage are comparatively easy: if you otherwise like a computer but think it doesn't have enough of one of these, you can add it yourself, now or later. It's cheap and easy, so this shouldn't be a reason to cross off an otherwise quality option.
Still, the question is what you want to spend, what you think is worth your money. Think about the above info, decide what's worth your money in general, and if you have more specific questions, please feel free to keep asking.
