Yes you can......IMC is the actual manufacturer of the HD headsets....
Best pricing I have seen for the IMC headsets is thru Sierra-MC http://www.sierra-mc.com/products.asp?cat=248 and then get which "pin" (should be 7pin for '98 and newer HD's) and the type type you want (fullface, Flip/modular, Half or what I have helmet-less which also works with half.
Lot's of choices, as some have said IMC (forum sponsor); J&M (another forum sponsor) is another alternative. Depends on what you are looking for. They are both different, but ultimately the same.