OK - found a link to the skimmer you are talking about - right?
http://www.aqua-africa.co.za/NonoDocSkimmers.asp
This one?
I am sure it will do a decent job and won't look TOO intrusive (perhaps hide it away with some live-rock?) in a nano-tank....
http://www.marineaquariumsa.com/showthread.php?t=1132
And perhaps the following for a "hang-on" over-flow:
http://www.guppiesforyuppies.co.za/prodtype.asp?PT_ID=374&strPageHistory=cat