Okay so after some thinking and a bit of research, I ended up ordering the- Hagen Fluval U2. I hope it will work like a charm. Do you think I made the right choice?
I use one of those filters in my clawed frog grow out tank. It works fine for me. I clean it out about once a month. I did notice it had stopped working a while back but I smacked it and now it's working again, pretty weird.