OP- As previously mentioned, you're in an incredibly lucky situation having dual citizenship.
To echo the thoughts of my extensive research over the last 5 months, go for the US route. Conduct your training wherever you feel the instructors will look after you best. You can then flight instruct and are not bound to any particular school and have no subsequent visa issues. From there, you can steadily climb the ladder of aviation.
What a fortunate situation you've found yourself in. Can't say I agree with the US immigration policy of allowing citizenship for merely being born there but nevertheless enjoy :-)