Wow! That looks amazing. How many gallons is the tank? The back part makes a perfect refugium.
What's in the basket, corals?
As for the Koralias, you can either:
a) Get stronger magnets.
b) Make an upside down "J" type plexi glass bracket, attach the K4's on the long end and hook the other end over the lip of the tank. This will allow you to hang them on any of the edges.
c) Make a pvc support stand, drill a hole in a couple pieces of LR (the holes must be big enough for the pvc to fit through), stack/bead them through the pvc and attach the K4's at the top (you could also use clear acrylic rods). You could place them anywhere in the tank. Just bury the pvc base in the sand or insert the pvc/rod in a larger, sturdy, drilled rock.