Peter, if you intend to store and the play the ripped DVDs in iTunes you then this is not an easy task to accomplish. iTunes was designed to play films downloaded from the itunes store. Typically a ripped DVD will not be in this format - so "utilities" have to be used to fool iTunes into accepting these files.

I cannot comment on whether the graphics card in your mac pro can be configured to output 1080p.

Nick

Sources: Auralic Aries G1 & Re-plinthed Thorens TD-150/ISOkinetik Power Supply/Linn Ittok/AT33PTG/Trichord Dino
Speakers: DSP3100
Other: QNAP TS-451+ as a Plex and Roon Server, Samsung 4k TV-Plex Client