OP wrote:
"Sounds like the odds of finding a 2019 27” with a SSD would be super random."
As colodane wrote in reply 25 above... "educate yourself".
No one else can do this for you -- it's up to you.
The best way to get a 2017 or 2019 iMac, configured the way you like, is from the Apple online refurbished store, which is here:
Save up to 15% on a refurbished iMac. Tested and certified by Apple including a 1-year warranty. Free delivery and returns.
www.apple.com
But you must
"learn the rules" about shopping at the online refurbished store:
- items come in, and go out, often quickly.
- you must check (literally) morning, noon, suppertime and night to see what's available.
- you must check CAREFULLY the configurations of items, to be sure you're getting what you want.
- you must be READY TO BUY when you see something you want -- it may be gone in hours or even minutes.
Apple refurbished Macs come with the same 1-year warranty as new.
You can also buy AppleCare for them, if you wish.