I use a spray bar that runs the full length of my tank plus two koralia nano's (one top, one bottom) that push water towards the filter intake (well, currently just one since I broke the impeller on one of them taking it apart to clean it and need to get a replacement).
The spray bar does a good job of (gently) circulating water through the tank, the powerheads mostly help with pushing any debris towards the intake. They produce a fairly gentle current as well - my fish don't seem to have any problems swimming against it. I have them running on a wave timer so they aren't running constantly.
Item # 180489727574 on ebay is the spray bar I have. I considered DIY but I don't think I could have done it any cheaper. I used all but 2 sections of the spray bar in my 55g and it runs the entire length of the back. One of the elbows it came with fit the rubber end of the original ribbed fluval hose perfectly. I have a 306 so it should also work fine with your 406