Leonel Galeano (Independiente) is a great prospect, although he might be a little (too) young for you Arsenal first XI. Have a look at Salvatore Bocchetti (Rubin); bit older, quality, and won't cost you much. Dejan Lovren (Olympique Lyonnais) is good, too. Same goes for Davide Astori (Cagliari). Or wait for Tottenham to list Sébastian Bassong.