wysiwyg for Heroku with Django and S3 static file hosting
I use the Suit skin for Django admin, and one of the WYSIWYG options is something called Redactor. That's a quite nice-looking text editor that works well. It can sometimes produce a little garbage HTML but nothing too scary or malformed (just the odd empty div or span).
What you'll also probably want to do is use CloudFront to distribute your static and media files, and whitelist the Origin HTTP header. There are also some cross-domain rules you can add to your bucket.
My CORS (Cross-Origin Resource Sharing) settings are really bastardised form people who know more than I do, so if you want a clean approach I'd suggest checking the Amazon docs on the subject. They go through the details of setting all that up. This simpler guide might also help, as it just goes into the basic CORS settings.
But I've got that running and so far haven't come up against any cross-domain issues.
Hope that helps.