No advice here, however I spent 7 months in Sth America back in 2000.....travelled from top to bottom, and spent about a month in Peru.
I didnt kite back then, but zig zagged all the way down the coast into Chile, and recall a hell of a lot of coastline, some of it good, some bad, some areas very remote, and some nice uncrowded beaches near towns (a bit of surf here and there). Anyway thinking back, plenty of spots that would be great to kite if the wind was on. Be worth researching further!
Enjoy your trip