I just went through this and got the euro one or something. The ghost skimmer reviews weren't very good and the one I got was 1/3 of the price with much better reviews. Coralfish12g has a good review/set up of the one I'm talking about.
Any other answers on this? I am interested myself about this topic. I've heard the Tunze 9001 is good, but you have to change the return pump and plumbing into 2 smaller separate pumps to make it fit in the back. I was looking for a good option without changing all the plumbing right away.