Is Safari available for Windows at all?

No. Apple stopped making Safari for Windows years ago, the last version was 5.1.7 back in 2012. You can still find that old installer floating around but don't bother, it's so out of date that half the web won't render in it and it gets no security fixes. If you need Safari to test how a site looks, the only real options are a Mac (or a friend's) or one of the paid cloud testing services that run real Safari for you. If it's your iCloud passwords you're after, that's a different story. Install iCloud for Windows and it comes with a passwords extension for Chrome and Edge.