How about EvoArticles or pmachine Expression Engine ? both looks promising on seo side not sure about how well they word as a CMS, since both are Article Mangement tools.
I think that evo article is not bad at all, as you said it is an article manager but for simple websites it would do it with light custom programming.
I think you should try Word Press, easy to install. Most of the plug in support Word Press. It's very easy to learn online (as I have learn). Google is my teacher. Lacks of themes and template available for word press. It's awesome experience. Bloggers prefer wordpress just because of their easy functionality. You can hire any custom wordpress designer to design your theme. Theme can be easily customizable for any one include those who don't know coding. Thanks for sharing.