When I import photos from whatever source, I direct Aperture to copy the files to the above directories, however it only allows me to select YEAR/MONTH/DAY, it will not allow me to choose project name as part of the directory structure (without simply ignoring the month and year).
Does anyone know if i can do this in the first instance from the import page?! or am i missing something very simple here?
Yes, you can do this during import.
Not sure what you mean by "it only allows me to select YEAR/MONTH/DAY". In the Subfolder drop-down field you can choose whatever Folder Namng Preset you want, or create a new one.
So in the import panel under Aperture Library, set Store Files to the external volume, and create a Folder Naming Preset for the Subfolder setting, and use it. The preset will look like this:
media/photos/Image Year/Image Month/Project Name￼