What is the best free option for automatic ftp sync with finder?
TextWrangler

You can use BareBones' Text Wranger. It is a free texteditor with onboard ftp capability. TextWrangler is BBEdit's little brother, and BBEdit is one of the best text editors. I use this text editor at least since Mac OS 7.6 And, just like BBEdit, TextWrangler does not suck.