Plenty of bidets have a storage tank with pre heated water or heat the water prior to spraying your butt hole.

I’ve used Kobo and Ebooks.com, and import into my Calibre library. I know some authors have a way to purchase directly on their site.

It absolutely does. https://plugins.calibre-ebook.com/ there is a KFX input plugin. Also, if using an older version of kindle for PC you can batch download your whole library and import to Calibre.