Check out www.blackjungle.com They have extensive walkthroughs with pictures on creating waterfall, river, and pond style setups. They mainly work with Dendros, but this can be used for all species.
I vote for the cork bark idea, just find a good chunk of cork brk that could be used as a river and attach it to the waterfall and let it run out into the pond area. This is where having a false bottom is a huge advantage.