I think your Koralia should give you pretty good flow over the entire tank, as long as it isn't pointing up or down, but kinda toward the middle of the tank.
I actually picked up a couple of Koralia #2 units for my 55 last night and placed one on each end of my tank and got rid of the other powerheads. I had to watch each of my corals to see how they did. I moved one of the new Koralias to get flow to one corner where I have an 8 branch hammer coral and then saw that my other branch coral was getting way too much flow. After a few more moves, it looks like all the corals were moving pretty nicely. I then saw that my new mushroom was about to be blown off its rock so I moved that behind another rock.
The placement that ended up working for my tank resulted in my Koralias placed 3-4 inches from the top, pointed slightly down and to the side. Since my coeals are mostly near the bottom of my tank, I can tell from their movement that they are indeed getting water flow down there.
Hope this helps!