Here's another possible avenue... the MAVNI Program. I'm not up on current events concerning this and how it relates to SF accessions, but apparently some folks are headed to expedited citizenship & eventual SF by this roundabout route. You'll have to do your own digging and research. You have one of the desired languages (Portuguese). There's a query application included in the last link; it specifically asks for interest in serving with Army SOF (operationally or in a support capacity):

http://www.scout.com/military/warrio...n-u-s-military

http://www.military.com/daily-news/2...g-program.html

http://justanotherasian.blogspot.com...-airborne.html

https://my.goarmy.com/info/form/GetB...rl=/info/mavni