I live in an area where the closest Shi’a masjid is too far away to travel during work on Jummah. What should I do? Should I pray regular Dhuhr at work only or pray Dhuhr at work then try to go to a Sunni Jummah service.

You should pray Zuhr at work. If you go to the jumah service of a non shia then you would still need to make salat al zuhr.