Here's the link to the various packages compared in a table format.
http://www.adobe.com/products/creativesuite/buying-guide.html

Below are the links to the different packages on Amazon. CS6 is selling as a retail box, download and as a monthly Creative Cloud subscription.

Design Standard
Retail box: Windows (Edu) | Mac (Edu)
Download: Windows (Edu) | Mac (Edu)

Design & Web Premium
Retail box: Windows (Edu) | Mac (Edu)
Download: Windows (Edu) | Mac (Edu)

Production Premium
Retail box: Windows (Edu) | Mac (Edu)
Download: Windows (Edu) | Mac (Edu)

Master Collection
Retail box: Windows (Edu) | Mac (Edu)
Download: Windows (Edu) | Mac (Edu)

Photoshop
Retail box: Windows | Mac
Download: Windows | Mac

Photoshop Extended
Retail box: Window (Edu) | Mac (Edu)
Download: Windows (Edu) | Mac (Edu)