If you are looking for an under the stand sump. I use the marine land C3 sump for my 60 cube because of the small foot print. Here is a link. I took out the bio wheels and used the filter compartments to house my carbon etc.... You can get the exact specs here with this link to make sure it would fit. I think it is like 14 x 16 x 21 tall at the back. I used the marine land pro 100 skimmer with it and it worked great because it has a shelf for it to sit in where the water le el is always constant. But i am sure another type of skimmer would also work fine.
Aquarium Wet/Dry Filters: Marineland C3 Sump Filtration System