MIS/BIS/CIS

If the Information Systems program is in CS Department, it will require more CS courses. If the program is in Business school then you can learn undergraduate level business knowledge in addition to programming. Many Chinese fellows majoring in MIS end up in programming and database development. Some end up in financial analyst. Some don't have job :) (maily those graduated in a bad job market)

If you don't like your PHD major, go ahead change it ASAP!!!! CIS/MIS to a Physics PhD is a piece of cake. I am sure you will do well in Information Systems world. You can call desired IS program admission office and ask for their student employment placement stats and how flexible is the curriculum so you can choose more programming course if you'd like to.

good luck!