The computer has nothing to do with the amount of assets you install, its the HDD or SSD space that matters.
2000-3000 assets is not really that crazy, there are enough people with more.
If you are looking for a new PC for rendering in general i'd say:
a good ryzen cpu (lets say the 3600 for example), 16-32 GB ram (16 is the absolut minimum i'd take) and a decent nvidia gpu of course preferably one of the 3000 series but they aren't easy to come by.
Not to forget enough storage space. 2TB at least because you will keep installing assets anyway.