A buddy of mine has a rental biz near Quepos. He has all the Riot boats, including Turbos. Just south of Quepos is the Rio Savagre, it as up to Class IV rapids. But it also has a long stretch of Class II-III WW. There is also a play spot right in Quepos, but I am not sure if it would be in this time of year.
My buddy can be reached at [email protected]
He is on the road right now, in Colorado actually, but he checks his email frequently.
Take it easy,