The latest releases of both JAM! and JAM! Lite will include a new full screen article editing option.  While editing your Joomla! article, you'll get a preview of the article text and right above it, a button that reads "Edit (Full Screen)".  When clicked, this button will take you to a new full screen to edit your article's html.  This gives you much more room and makes it much easier to see the text while editing.  Here's a couple of shots from JAM! Lite: