I didn't have much luck with plants with that setup (I had herbivorous fish in there), but the fish did well!
The best I could do for the plants (before they were eaten) was to position the filters at the ends of the tank and put the taller plants in the middle. I also had big rocks scattered around and that created some peaceful pockets. Not a great solution, but I didn't really mess with it too much because my plants didn't live that long. I believe some people shove chunks of sponge on the lip of the output to soften the waves. If you have big rocks, you can artfully place them beneath the output to break up the stream.
You might need a new topic for that subject to get more attention--I know people use them more successfully than I did! (I had to retire my AC500s in order to get the tank closer to the wall...plants still won't live with those fish!)