you should look into the all-glass Mega Flow wet/dry filters hey are pretty cheap compared to "custom" ones made by local companies and they include bio balls and most of the plumbing if not all of them.
all the media will be under water.......the wet dry concept to to provide the bacteria with max oxygen.....like in a bio tower....the wet dry sump is a compact version
lolololololol Nahh that wouldnt work, all the piping would have to be filled up to get the water back in the tank, so there wouldnt be and dry, therefore no oxygenating.
yeah would be a very low oxygen filtration which would make the a;ready low amount of bio area even less effective , i say if you have space for this then your better off with a sump imo.