Jews for Jesus. Are they still viable? And if so, are they really Jews? Are they believers in Saints if they accept Jesus? What up?

I'm not sure what that specific group believes ... whether Jesus was actually their prophesied Messiah, or if he was just another Rabbi/Teacher.

I know there are groups of Jews who believe Jesus was the Messiah.

Jesus was a Jew. So were all of his disciples. 
Can you name the Jews who are Saints in Christianity. There are nearly two dozen. 

Yes, there are Messianic Jews still around. They believe in the New Testament and also still follow the food laws and celebrate the feasts and festivals in the Tanak (Old Testament). They also use Hebrew words during their services. They call Jesus, Yeshua. 

Christians are technically 'modified jews'.