Having a look around it appears to available to purchase for streaming on Amazon.com in both the theatrical and complete novel versions.
I see it now. I have trouble believing it actually is the theatrical in HD, though. If that is, that would be the first and only official release of the theatrical cut in HD ever. I don’t know where they would have gotten an HD master for the theatrical version, since Coppola got a little Lucas-y and has never wanted an HD release of the theatrical cut. Upon that, the restoration in 2005 which added the scenes, also took out some scenes and redid titles. Upon that, any release besides the VHS copy that has the wrong WB logo. More recent home video releases have the “shield” logo, while the true theatrical cut has the “worm” logo used in the 70s and 80s. So the amazon stream, if it really is a shorter cut in HD, will probably not be the “true” theatrical cut. I’m not sure, though. I haven’t watched the amazon stream version in HD of the “theatrical” cut.