Have a look at the Deltec MCE600. It's very neat for a hang on, and deltec have a very good reputation for skimmers - no pump in the tank either, and you can pick up secomd hand ones quite regularly.
I would take the sponges out of the filter unless you want to take them out and clean them every few days. If you want to filter particulate matter out, use some filter wool in it (but this will need changing weekly
Sounds like you are off to a good start
