Paolo Di Canio has brought in Valentin Roberge, Cabral and Modibo Diakite on free transfers so far, and has also set his sights on Orban.
The 24-year-old's agent Filippo Colasanto claimed that his client would be an ideal signing for the Premier League, but has other offers on the table from teams in Spain to consider.
Colasanto told tuttomercatoweb: "Sunderland have moved in a concrete and correct way for Orban, making an offer to the player's family.
"We talked about it, but the boy wants to take his time and choose at the end of the Argentine championship.
"There are several opportunities for him in Spain, so the choice is between these two countries.
"He is physically very strong and he would be perfect for the Premier League."