I've been looking at the different stream setups on here (found a grand total of 2 now) and I'd like to do something similar in the future. Now I have no experience with powerheads but I had a thought (shocker I know). You said you were looking for differing currents and eddies, what about staggering the height of the powerheads? It would make no difference with the intakes but making the heads at different heights should "mess up" the flow giving you eddies and such. In fact, I think it would be very similar to nature with the water coming from over rocks and uneven stream bed. Any thoughts pro or con? Do like your tank very much in case I hadn't already said so.Added a video of the currents. The tank is clearing up nicely. Looking for stocking inhabitants now and have made some email contacts toward that end. I don't know the proper way to post youtube vids but this link works. Pay no attention to the heavy breathing. The guy who shot the vid was very excited. LOL
http://youtu.be/h4u-48T4oyI
Mark