@takayan, You probably won't see much difference either way. The Super Marin has a great design, however you will get a little more reaction time in the Deluxe series.
@joao, A 250 model will be too big on a 180g system, period. It's just too much skimmer for that small water volume. You will get much better performance sticking with a 200 series from Royal-Exclusiv.