I’m not familiar with the Kobo, but here is what I do with my Mac Mini/Onyx Boox combination.
I download pretty much all of my ebooks as epub. Hazel on the Mini automatically moves epubs to a Calibre watch directory. Then I remote into my Mini with my laptop, start Calibre’s web server, browse to Calibre’s address from my Boox, and download the epubs to it. Lastly I shut down Calibre’s web server.
It’s not a completely turnkey solution but I don’t have to get out of my recliner for any step of it.
Looks to me like you’re in the sci fi/thriller genre. There’s a lot in that category. Seems you like the classics too. Have you tried Phillip K. Dick? Dracula might be your cup of tea also.