As far as I know, there does not exist any true WP/Weaver compatible WYSIWYG Page/Post editor. You can only come close. Because of all sorts of things, not the least of which is that different browsers do not display things exactly the same, it is essentially currently impossible to have the page/post editor view correspond exactly to the final content on a browser.
BUT – if you just want more user styling options available such as font sizes, styles, and other things like that, the WP Edit plugin is probably the best available plugin.
Its defaults aren’t ideal to work with Weaver Xtreme, but a simple tweak of its font size options to use ems instead of pts makes it a perfect companion for Weaver Xtreme. It is highly recommended, and I’m thinking of adding it to the suggested plugins in the Weaver Xtreme plugin startup.
Thanks Weaver. That was the suggestion I needed. There are several to choose from and I just wanted to know which one worked best with Weaver Xtreme. By the way, I LOVE Weaver. This has made it possible to really work with WordPress.