Refurbed Mac ... Specs?

I am thinking of buying a refurbished Macbook, so is there a minimum OSX version I need to be aware of and also Xcode, for use with juce?
I have seen several OSX Lion laptops which seem very good value.

MacBook: Aluminium Late 2008; Early 2009 or newer
MacBook Air: Late 2008 or newer
MacBook Pro: 13-inch, Mid 2009 or newer; 15-inch, Mid/Late 2007 or newer; 17-inch, Late 2007 or newer

This way you can run the newest stuff (OSX 10.11 El Capitan, Xcode 7) and you won't risk running into JUCE problems that we can't support!

Very useful info.
Many thanks