My audible account is using the same amazon.com user id and password as my Kindle. They are both Amazon US account.

Here's an example of Stephen King's The Stand. Pretty popular book. The Kindle version is this:

https://www.amazon.com/Stand-Stephen-King-ebook/dp/B001C4NXKM/ref=tmm_kin_swatch_0?_encoding=UTF8&qid=&sr=

In the Kindle page, I will click on the Buy button for Audible and it bring me to this page, stating that "this title is not available for you".

By Random House.

https://www.amazon.com/hz/audible/checkout?ref=adbl_dp_dt_cr_bb

But, I can see The Stand my Audible. This version:

Publisher: Hodder and Stoughton

https://www.audible.com/pd/The-Stand-Audiobook/B008K7S3E0?ref=a_library_t_c5_libItem_B008K7S3E0_0&pf_rd_p=80765e81-b10a-4f33-b1d3-ffb87793d047&pf_rd_r=91TKASC8YHX0SAX8HZM5&pageLoadId=Wuom3i3rs03vjZWj&creativeId=4ee810cf-ac8e-4eeb-8b79-40e176d0a225

The Stand in Audible is not linked to the Kindle.

Since it's not on your list yet, the first order of business should be to read The Stand.

https://www.amazon.com/Stand-Stephen-King-ebook/dp/B001C4NXKM

If you don't mind looking back at the classics, then definitely Earth Abides and even The Scarlet Plague.

https://www.amazon.com/Earth-Abides-George-R-Stewart-ebook/dp/B0042JSMQ4

https://www.amazon.com/Scarlet-Plague-100th-Anniversary-Collection/dp/1948132737