There's also Wintek. The reason you don't hear much about it is because Wintek is more for businesses.
You mentioned River Walk and I know that that's what they provide (live here).
Two tests I just ran with their internet,
Makes sense. I'd check with Main street Books/Second Flight. They're (now) owned by the same folks, so they probably have a good line on any book clubs.
If you want a good "entry" book to SF/fantasy, check out Becky Chambers - specifically, the Wayfarer series. Here's a link to the first one. They're very wholesome, lovely books. There's not exactly romance in them, but in her books, everyone is doing their best and nobody wants to hurt anyone else.
Besides Chambers, there's a decent number of SF/fantasy books that are also thrillers, mysteries, and romance! I think the book club just read Project Hail Mary, which was definitely thriller-esque.