Help need advice

Ok the 58g I help take care of is having a serious issue with the skimmer, except noone has any clue wth kind of skimmer it is. It's a 20g sump tank but the skimmer is actually made into one of the chambers, just the tube and top peice of the skimmer come off of it, it's making some god awful noises and not getting very much air into the chamber to circulate now though so need a good budget idea on how to replace this setup or attempt a repair but as i said before I dont think this comes apart

 

So I'm debating picking one of these up, Saltwater Marine Aquarium Water Quality & Filtration: Fission Power Skimmers by Current USA

If anyone has any advice or suggestions on them please feel free, Also as far as the sump I'm assuming I can just set a 20g tank below and put this in it and hook the drain line to it, then have my mag 9.5 in the tank for return as well?