@CuzzZoovier As with most games, the single most important component in determining how well a given laptop will run Sims 4 is the graphics card. An Nvidia 1650 will run all current packs together on ultra graphics settings with some room to spare. That may or may not be true by the time the game is out of development—we don't know how demanding future packs will be. But at the very least, a 1650 should always handle all Sims 4 content on a mix of high and ultra settings.
The next card up, the Nvidia 1660 ti, should always handle ultra settings easily and is kind of overkill for Sims 4, not that that's a bad thing. An Nvidia 2060 is only about 5% faster in gaming, although it depends in part on the game, and the cards faster than that are significantly more expensive.
Custom content by itself doesn't necessarily raise the demands of the game, but high poly (high-resolution) cc does, as it takes more resources to render than lower poly cc or EA items. So if you like using high poly cc, you may want a faster card than the 1650, although the 1660 ti should still be more than sufficient. It's not always obvious which items are high poly, but good creators will list the polygon count on their download pages, so you should at least be able to get an idea of what you currently like to use in-game.
As far as the other components are concerned, there are only a few details to address. The processor matters, but any processor that comes with at least a 1650 will be more than strong enough for Sims 4. Most entry-level gaming laptops come with 8 GB memory, which is enough for Sims 4, but 16 GB would be convenient for other reasons. Still, RAM is the easiest component to upgrade: you should be able to find a matching 8 GB stick for under $50.
You mentioned wanting a lot of storage, and there are a number of options with a 512 GB solid state drive (the very fast kind), which is more than enough storage for most people, even people who like to hoard cc and spare saves. There are only a few options with both a SSD large enough to hold Windows and Sims 4 plus a secondary mechanical drive for overflow storage, but they're out there too, and it's possible to add a 2.5" hard drive to most gaming laptops that don't already have one. Since the processor and graphics card generally can't be upgraded, those are usually the priorities.
For your budget, you could get a laptop with an Nvidia 1660 ti or even a 2060. If you're not ready to buy yet, there's not much point in picking out what you want, since prices can change quickly. But here are some examples of what's out there, so you have an idea of your options.
In the category of laptops with an Nvidia 1650, these two are both $700 and are quite similar, except for their storage options. They're "coming soon," but maybe you don't mind waiting.
https://www.bhphotovideo.com/c/product/1561720-REG/lenovo_81y4001wus_l350_15_i5_10300_8gb_256gb.html
https://www.bhphotovideo.com/c/product/1560811-REG/acer_nh_q5uaa_008_nitro_i5_9300h_8gb_512gb_ssd.html
This is the cheapest good option I saw that's available now:
https://www.bestbuy.com/site/acer-nitro-5-17-3-gaming-laptop-intel-core-i5-8gb-memory-nvidia-geforce-gtx-1650-512gb-solid-state-drive-black/6345056.p?skuId=6345056
Laptops with a 1660 ti generally start at $900, but with less storage than you'd want. This one is $950, although one thing to note is if you wanted to add more memory, you'd need to buy the full 16 GB, since this one comes with 2x4 GB rather than 1x8 GB.
https://www.dell.com/en-us/shop/gaming-laptops/dell-g3-15-gaming-laptop/spd/g-series-15-3590-laptop/gn3590dovds
For $1,000 and a several week wait, you could get a much stronger processor plus 16 GB memory already installed. Or for $1,100, you could get a full terabyte of SSD storage in otherwise the same computer, other than the slightly larger screen.
https://www.bhphotovideo.com/c/product/1558021-REG/asus_tuf506iu_es74_tuf_a17_gaming_laptop.html
https://www.bhphotovideo.com/c/product/1558023-REG/asus_tuf706iu_as76_tuf_a17_gaming_laptop.html
Among the options available now are a couple of MSI laptops with a 1660 ti and a stronger processor, and a 2060 and a weaker (but good enough) processor, both with 8 GB memory and a 512 GB SSD.
https://www.bestbuy.com/site/msi-gf65-9sd-15-6-laptop-intel-core-i7-8gb-memory-nvidia-geforce-gtx-1660-ti-512gb-ssd-black/6408066.p?skuId=6408066
https://www.bestbuy.com/site/msi-gf65-9sexr-15-6-laptop-intel-core-i5-8gb-memory-nvidia-geforce-rtx-2060-512gb-ssd-black/6408073.p?skuId=6408073
If you have more questions, please feel free to ask. And whenever you're ready to buy, you're welcome to link the options you're considering for a second opinion, or ask about anything new that might have become available in the interim.