Yes, NOMAD can work in Southern hemisphere. The alignment target of the Southern hemisphere is Sigma Octantis or the South Celestial Pole.
If you already have a ballhead, you can check the phone mount kit: https://www.moveshootmove.com/collections/move-shoot-move-rotator/products/msm-rotator-for-star-tracking-time-lapse-panorama-photography?variant=42128160030937
This phone mount is a polar alignment tool, it can help you attach the phone at the backside of NOMAD, then use the app Photopills/Stellarium to guide the adjustment to align NOMAD to Sigma Octantis or the South Celestial Pole. There is a video guide:https://www.youtube.com/watch?v=bfHH0_bkbKE, although the alignment target in the video is Polaris, the using method is the same, you just need to align to a different target.
One ballhead is to connect NOMAD to the tripod then another one is to connect the camera to NOMAD. This kit will come with one ballhead.