Nunamakt:

I'll try to briefly give you my 2 cents.

For a 180, most reefkeepers would use 3 bulbs, either 250W "double ended" or 400W "mogule" These refer to the type of socket the bulb plugs into; the mogule bulb just screw into the socket like a regular light bulb. The double ended bulbs clip into sockets at both ends of the bulb. This is the european style, and require a different ballast, which is the power supply, typically a big box that you plug the lights fixtures into, then plug into the wall. If you're moving to europe, you could take these fixtures with you, because the D.E. bulbs were originally designed to run on 220W AC power. The ballast might not work, but some of these have switchable A.C. requirements. You could contact sunlight supply or PFO, two leading brands of aquarium lighting, about that.

The 250W D.E. bulbs are comparable in intensity to the 400W mogule base bulbs.

Keep in mind, this is intense light for keeping the most light demanding corals like acropora, etc.. and tridacna clams. Many people use less light for average aquariums.

HTH
Matt