HN7700S Modem to replace HN7000s on Pro Plus plan?

OK, I FINALLY got the modem from the Amazon seller (as discussed in this thread  in the tech section:  Modem constantly resetting  )  (didn't actually ship until two weeks after he sent me the tracking number) 

Unfortunately, it is a 7700 modem instead of a 7000 modem.  From my research, the 7700 modem is pretty much the same as a 7000 , but with an extra  LAN line, and a phone line and a serial port, but will do the basic stuff that my 7000 does, and is compatible with my other equipment.

But I found  an old discussion on an OFF- Hughesnet Forum that said that Hughes will not commission the HN7700S modem on anything but a Business account..  I think my old Pro Plus account is kind of half way between a Home account and a Business account.  While  my 7000 modem is working now, I'd sure like to have this 7700 modem for a backup since Hughes doesn't  have any replacement units for my system at all, and I'd rather not  go through the hassle of returning it to the Amazon seller or give  bad feedback for false advertising......