1st, PPro is not designed for, and has problems with, a network
Win Server is NOT supported http://forums.adobe.com/thread/851602
Not in a Network environment http://forums.adobe.com/thread/771151
-a work around, of sorts http://forums.adobe.com/thread/957523
-and not on a "domain" http://forums.adobe.com/thread/858977
2nd, to go over 16gig of ram, you need Win7 64bit PRO, not the Home edition... so the answer depends on your hardware
I recommend Professional myself. It has all the features you'll need and few that you don't.