Double check what you've got for the Koralias...
Unless things are different where you are (UK?), the new generation Koralias (the Evos or Evolutions) won't work with the Koralia wavemaker that came out a couple years ago. That wavemaker control unit Hydor sells is made specifically for their DC
-voltage powerheads. The plug on those units will not go in to a wall socket, but only into the socket on the wavemaker unit. The Evos will plug directly into the wall socket. Hydor calls the Evos "controllable" because they can be turned on and off over the course of seconds or minutes without harming the powerhead. With the older Koralias, if you tried to do this, they would break. The Evos can be "controlled" (turned on and off) with either timers or an aquarium controller. But they won't work with the Hydro Koralia Wavemaker controller. Hope that makes sense.
Sounds like you have everything you need for the basic tank, less the heater, refractometer, test kits, salt, and a multitude of other things you'll find over the next few months that you can't live without!. I'm not familiar with the unit you're getting, but you might want to double check that the skimmer will fit in your sump once you get your return pump (which sounds like it's included) in there.