This question has been answered by sottwell. See the first response.
The best thing to do would be setup MODX and have a play to see how comfortable you feel with the different ways to do things
An indirect answer but a method that works for me...
I use WinSCP as an SFTP client for the single reason that I can use it to right click on any remote file and then edit it in my IDE (I happen to use Komodo). Click save in the IDE and WinSCP updates the remote file (CSS, HTML - any text based file).