Hate to go against your store fellow there as it may be the only eheim type he can easily get but within the forum we get rather picky about our eheims. We recommend -against- the Ecco series, against the "thermo" models and somewhat against the "wet/dry" models as already discussed. The thermo models have a problem with the temperature sensors in that salt messes them up (we don't recommend salt, usually ever, but it can still happen, so...) The complaint about the Ecco series is that the entire line was made off in asia somewhere (not that there's anything wrong with that) and is not the same as the Classic, Pro, Pro II, and Pro 3 model lines made in Germany. These last mentioned lines are the ones that are so sought after on the forum. Depending on your tank volume and goals I really have a feeling the Pro or Pro II lines would be the best thing for you even if its a bit of an adventure actualy getting your hands on the right filter (it was for me, that's for sure!)
~~waterdrop~~