Hello,
I am an expert in elearning systems and development including instructional design with over 13 years of experience and would be happy to work with you on your project.
I think Moodle is a good choice as it is now a powerful and stable system, free and have a lot of plugins. Now the recent version is 2.7, but the latter you go the less plugins available as developers who developed plugins need sometime to update their plugins to a recent Moodle version if this interests them, but at the same time, you should not go back too long as the recent Moodle versions provide powerful functionality plus many built-in plugins which where addition before a few years.
Version 2.6 has been there for sometime, even though that it is not long, but it supports many plugins, if this is ok for the moment, then you can add some plugins later in a few months, then this is the best version to choose, otherwise, you may go down in version until 2.4, most of the plugins are available for this version, but not less than this version as it looses power and stability.
If you choose version 2.6, which again I think the best, there are some plugins that are not free or require paid online services.
I here used most of the allowed characters to write, if you want to continue please discuss this project with me on PM.
Awaiting your call,
Best regards,