Well, it's typically recommended that you go "plus 1" on your skimmer size, meaning go a size up from manufacturer's spec over your tank size, but if you've got a lighter to medium bioload, this should do pretty good:
Reef Octopus NWB200 8” Pinwheel In Sump Protein Skimmer - Bulk Reef Supply
I've got the size down from that one (NWB150), and it is a kick-butt skimmer. If you've got, or plan on, a heavier bioload in your tank, you may want something rated at a little higher capacity.