I have to give my child a Tragedeigh name

I'm American and my wife is Vietnamese. We live in Vietnam. Under the law, the only foreign name a child can have is the father's surname if the father is foreign. But we want a name that sounds English. So, for a girl we have Mai Ly (Miley) or Cat Thy (Cathy) and for a boy Vinh Sen (Vincent) or Binh Gia Minh (Benjamin)