Any of those processors would be fine for Sims 3. If you want to futureproof your computer a bit though, get the Ryzen 5 3600. It's much stronger than the 3200G and 3400G (and outperforms the 2700 as well), so it will be able to keep up with new apps, including games, for longer than the others. It also means that if you want, you'll be able to swap out the graphics card in a few years without worrying about whether the CPU can keep up. There's not much point in getting the 3600X though, unless you plan to overclock your system at some point.
The other specs are all good or great for TS3. The 1660 is overkill—you'd be more than fine with a 1650. But you might want the faster card for other purposes, like other games.
If you have a bit more money to spare, upgrading the SSD to a 512 GB model would be a good investment. A 256 GB drive is enough for Sims 3 plus all of your user content, but it still might be somewhat of a tight fit. So you might end up needing to install other apps to the HDD, or shift other files back and forth to keep enough space free. You wouldn't need to worry about that with a 512 GB drive, at least up to a point.
It might be nice to have more memory too, but it's certainly not necessary for TS3. RAM is cheap right now though, so it's worth considering. Getting 16 GB would make multitasking easier, especially if you like having browser windows open while you play.
I'm also curious about the power supply. You didn't mention it, but in many ways, it's the single most important component. Getting a cheap model can negatively impact your entire system, even if everything else is working smoothly.
Still, this is a very good computer for Sims 3, even as is. You shouldn't have any trouble playing on ultra graphics settings, beyond the limits of the game itself.
