Sierra was my top choice but I changed my mind... I posted a message in the aviation message board (www.flightinfo.com) and an old instructor of the school replied. He told me that once you take your CFI certificates, you have to find your own students, in order to build time! He spent there 1 year and built 150 hours. Of course, this is not acceptable, since I can only stay in the US for 2 years.