Okay, Cool, I found
CodeMirror. It's AWESOME.
SADLY, The more formatting and wikitext I add, like headers, and bullet points, the more out of sync the preview gets with my edit window, until I can't actually see new content I'm typing! I've got to have a way to keep the visible preview stay with where the cursor is...
Is there any fix for this? Right now, I've got this awful feeling of SO CLOSE! Yet SO FAR! :(
also, Why does the side bar just keep getting bigger and bigger? I don't want a huge side bar, I want the main area to get bigger as the viewing area expands, not the side bar... it makes the live preview really tiny and narrow. :(