I have tried the various tools available for epub createn. Neither is what I really am looking for.
Sigil looks the most promising. Hower, there are a few quirks I don't like. Perhaps I will post a message in the forum for that. Major quirks are no embedded font option and the CSS handling. I understand the fact that there is some internal CSS in the HTML which is exported into a CSS upon exporting, but I would like to attach my own CSS to it.

With eCub I really like the flexibility of the TOC handling. Editing is not so nice though.
Editing and creating the XHTML files is not that cumbersome. I found that what takes the most time, is creating the content.opf and the toc.ncx. For compiling the ebook I have created a simple batch script which outputs the ePub. Does anyone know of a simple tool that just looks in de subdirectory and creates the content.opf and toc.ncx? I understand that some hand work is required later in the toc.ncx for sequence purposes.