As a NES, but not a teacher, if used, I would have placed the "or not" after the word "whether", or rewritten it to say:
"Please confirm that (or "advise whether or not") you require the RMU and HV to be supplied by the contractor"
Hope this helps
PS The wording (particularly "confirm that" vs "advise....not") may be determined by whether you (as presumably the contractor) really want to or have the time to price/supply such items (which you presumably have to buy from others) i.e you may wish to steer them one way or the other based on your risk in pricing/supplying them.
Student or Learner