There are many more rivers down there than just the Futa also
The Futa has a class IV section,if memory serves it is the Macal section
There are also plenty of other rivers around,some just over the border in Argentina.Check out
www.exchile.com This is Chris Spelius' outfit down there; camping,lodge,guides,drivers,and people in general to hook up with
I've done both the Pucon area and the Futa region; loved em both
Futa is a little more out there do it seemed much more adventurous