I've just added support for the Amazon / AWS Polly support in Language Tools. You should now see 62 new voices, with an interesting mix of English / European voices, one Japanese, one Korean and others. Not all voices are neural-generated, but the standard voices sound pretty good.
I'll be working to add Amazon to AwesomeTTS soon.
Want to get started with Language Tools ? Read this: https://www.patreon.com/posts/46269121