Dell Optiplex 780 minitower adding SSD and upgrade RAM up to 16GB?

Hello, I have a Dell Optiplex 780 Minitower. It already has 8GB ram installed two 4GB dimms DDR3. There are another two slots.

Can I add another two dimms so to get up to 16 GB? There are two manuals available in Dell Official page. One manual mentions it can only get up to 8GB and the other manual says it can handle up to 16 GB.  So which one is correct?

Also, I want to install a 500 GB Solid State Drive.  Is it possible?  It already has a 160 GB hard disk but I want to replace it with a Solid State Drive up to 500 GB.  Is there a specification for this? SATA II? SATA III?

Thanks!