Unfortunately, I think that the answer is "no".
I've also answered your other thread about using Live Writer, which I don't believe is possible; I just tried to set it up again, and it still doesn't work. Live Writer is built for blogs.
EDIT: SharePoint is a Web-based application, so that's the editor: the browser. You can enhance SharePoint to work better by writing your own coe or using third party tools, but you're still working in the browser.
If you have specific requirements (other than "We are not so happy with the built in HTML one (because of image support)"), I'm sure that there are ways to make SharePoint work better for the specific requirement.