For what the OP is asking --- as another reply already mentioned, the Harmony hub works with Harmony remotes. So if you just want to use the factory remotes for your own setup then either the Niles or Xantech pieces you mentioned will do what you want.

Both the Niles and Xantech products are well established, long standing solutions. Like anything else, some will prefer one brand over the other. Just pick one and you'll be fine.