Before I continue, the "Jerusalem Council" is a Messianic Orthodox Jewish movement which basically follows the Talmud and Kaballah and don't believe that Jesus (or Yeshua as they say) is G-d. Neverthless they believe he is the messiah and they believe that the New Testament is from HaShem. Other than that they seem completely Orthodox Jews.
and here is the link about their views toward Jesus:
http://jerusalemcouncil.org/articles/faqs/is-yeshua-god/
Is a convert to Judaism through this movement is considered valid (according to True Orthodox Jewish Halakha) since they are not technically Christians (other than the belief that Jesus is the Jewish Messiah)?