For a stealthperson you're shouting (typing in a huge font) awfully loud
I never paddled in the Czech Repoublic myself but if you check the Dutch Kanoforum and ask for Wilko he can tell you a lot (he paddles a lot overthere).
AFAIK. there is a nice slalom course near Prague. Google (or scroogle, if you're paranoid like me
) is your friend ...
Cheers,
Michiel