Editors which treat indentation spaces as tabs only do that some of the time, which is annoying because it's inconsistent. There's also no need to "experiment with configurations", that's just a load of crap. Just put a line at the top or bottom of every file with the settings needed for that particular file. You don't even need a specific editor, there are plug-ins available for most IDEs and editors to read emacs or vim modelines. Anjuta supports both out of the box.
