Song School Latin

A few months ago I was having a terrible time deciding what to do for foreign language study.  Nik finally decided that he wanted to speak Latin like the Romans and like some knights once did.  That decision led us to Song School Latin.  We've really been enjoying it! 

The workbook is all that is needed.  It comes with a cd of songs that correspond to the lessons.  The songs are catchy, and while it isn't great music I do find myself singing them throughout the day.  We've worked through three chapters and Nik is already using his new vocabulary in everyday conversation.  What homeschooling mom wouldn't love that?!

Learning a Foreign Language

I can't decide when to start.  Now or in a few years? 

I can't decide what to use.  Rosetta Stone or Pimsleur?   (Our library system carries Pimsleur, so I'm leaning towards that or a combo of both.)

I can't even settle on what language to study!  Mandarin, Arabic, Spanish, French?

Thoughts?