"Admin Mods" worked fine for me (tried just now, after readuing your post). Using 1.9.4 on GNU/Linux server.
Go to "Admin mods > mods configuration"
I have it set as:
Enable Mods providing : [ ]
Mods local directory: mods
Mods remote server: http://tikiwiki.org/mods
Then go to "Mods Install/Uninstall", and select "update remote index"
This worked for me. Then I you select installing tikidav (unistalling previous version, if needed).
Ask again if in trouble. Tikidav author is also on edu.tw.o ...
However, there are already detected some errors under this tikidav release... (see this post)