Take iWeb design to next level

I don't know much about web design, but I am trying to learn. I just built a website on iWeb. I love the look, but hate the features of iWeb. I would like to transfer the site to a easy to use CMS with a WYSIWYG editor. Most of the CMS programs I keep reading about say they are template driven. I like the features of Joomla, but I was told I would need to convert my site to meet Joomla's standards. Anyone have any suggestions for me? I would hate to lose my iWeb creation.