After taking way too much time, I finally integrated Isso into my blog. It is developed by the same guy who writes Acrylamid, the blog engine I use, so the integration went very smooth. It uses SQLite for storing the comments and it is hosted on a subdomain. In this way, my blog is still static and super fast, but you still get comments, because they are loaded afterwards with AJAX.
It has quite good integration with Wordpress and I managed to import all the previous comments.
I'm looking forward to receiving many comments from you :D.