I'd go with 2.0.1 as newer versions work with the "hardened" DRM. I don't know if anyone is using the newer DRM yet, but it hasn't been broken so to be safe stick with ADE 2 which doesn't work with the newer DRM.
http://download.adobe.com/pub/adobe/..._Installer.dmg
Old thread about hardened DRM from back when ADE 3 was released...
https://www.mobileread.com/forums/sho...d.php?t=231939