When you say a twin stand pipe setup, are you talking about something like a durso standpipe drain and a single return, or are you talking about a dual drain?
What size is the display tank, and what size sump are you looking at?
Are you considering running a refugium in the sump, or a berlin style sump, or a wet dry setup? If you are not sure, what are the goals you are hoping to achieve with your sump and tank? For example, just for equipment, or lots of bio filtration, etc? What kind of tank is it? FOWLR