Meir Yimini OBM was one of the closest to Saba. Many things have been said of him, stories of ruach hakodesh, visits of Elijah the prophet, huge sums of money he would bring to Saba for the publishing of the holy books, it has also been said that Meir left over a Shas (Talmud) replete with glosses he annotated.
There was another person who was reputedly close to Saba and known for miracles - R' Nechemia from Bnei Brak - e.g. people are convinced that he did "kefitzas haderech" (traversing distances with great speed defying nature).