Toad for Oracle utilizes the SVN command-line client in order to interface with the server. Unfortunately, early versions of Tortoise didn’t include the command-line client with its installer, which is why you saw those posts. Newer versions of Tortoise do include it; however, you may have to make sure to select that option during the install process – I don’t think it’s selected to be installed by default.
As Dennis mentioned, CollabNet installs the command-line client by default. It’s also a “certified” client. As a result, it’s always a safe version to use with Toad.
Either one should work with Team Coding. The only thing you will need to make sure is that if you don’t have the svn executable in your path, you’ll need to explicitly set it in the Subversion options dialog.