Welcome to TRT!!!
i am not a fan of refugiums, they are just something else to feed. no real benefit. after saying that if you are interested in fragging corals and such this would make a nice growout tank. a growout tank will just have water, eggcrate stand, and the corals on the stand, that is it. i think a 75 could be a bit tall for a sump. it will work fine, but it is easier to use a shallow rubbermaid tank. if you are going to be pushing up 13' do not try and use the return as added flow. you should really think about putting in a CLS (
Closed Loop System). it is a much more economical way to add flow than trying to get a big enough pump to pump that high. not to mention balancing an overflow that distance is annoying and loud, when you move that much water.
G~