There are various factors to consider.. if you want to pay or have a Priority Pass, then you might want to consider LAX T3 for the Alaska Airlines Board Room lounge prior to the VX flight. Virgin does not have a relationship with them, but the lounge is close to the VX gates, has a beautiful panorama of the runways and is one of the better domestic airlines lounges that I have frequented. They even offer complimentary internet in addition to drinks and snack items.

I don't know about SNA, but I suspect there is no departure lounge if you fly out of there. Someone else can chide me if I am wrong about this comment.