Hi,
In the middle of your list, you have (what looks like) two lines that mention SSD. I'm thinking there must be an error, as they appear to contradict one another.
I will say that an SSD is a very common element on most any gaming PC today, and it does offer enhanced performance over a hard disk. I'd call it essential, TBH.
Also, even though the GPU you have specified is actually a very nice, reasonably powerful card, you probably want to read this thread:
<LINK>. The situation he presents is remarkably similar to yours, so it seems very relevant to what you've asked for input on.
It was created by another forum member who actually bought a new PC with a 1660Ti (a small step above the 1660, as you know). He discusses having performance issues, though his system handles other games well, and he's tried the usual suggestions by other forum members, to no avail (or at least some of them; regretfully there appears no actual conclusion in that thread, so I'm not sure what the outcome was) .
There are other threads/posts by members who run less powerful equipment than you list, and they report acceptable performance overall, with only occasional issues they're willing to live with.
Additionally, there are several involved discussions on the forum as of late, where several forum members assert that very high-end (though generally very expensive) hardware is key in overcoming the performance issues. There are several discussions; you can review these threads in the main forum, and make your own judgment as to what's 'worth it' to you. Your post reads as if you're considering this hardware configuration but haven't bought anything yet, so maybe you want to consider higher-end than what you've listed.
My opinion is the hardware you listed should run fine of itself, based on my own first hand, extensive experience with faster and slower hardware (I build ~10-12 systems for others a year, using both new and 're-homed' components, as a "semi-compensating" hobby). As everyone knows, it depends on how the individual game runs. Some are much better optimized than others.
Good luck, I hope it helps, any questions welcome.