Which toolbox version will work?

The University has a site license for Matlab, and the license includes many toolboxes. I've installed various versions of Matlab on 3 computers, and the site license covers each of these. However, the database toolbox is not included, so I must purchase it. There are three questions, please: 1. Will the database toolbox for R2014a work for R2013a and R2009b? 2. Is it best to purchase the toolbox meant for the student version or the education version? Does this matter or are the toolboxes the same? 3. If the toolbox works on all recent versions of Matlab, must I purchase the same database toolbox for each of the 3 computers as though each purchase were a "license" for the toolbox?

Thank you for your advice!