Very Cool Kirk!!!
I have always loved this chord progression since I learnt it, & it's nice to see you do it using open chords.
By a strange coincidence I stumbled across this the other day, it's how to add a Flamenco Rhumba right hand technique to this very progression (well almost this progression, they are not as adventurous as you & start on Am), anyway scary stuff not for the faint hearted. I hope one day when I get enough mojo I will be able to play it. Hope you enjoy it
Dan
http://www.youtube.com/watch?v=O-2y2ovSkCU