i just made one. its not all that hard. all i used was 100% silicon and acrylic panels on a 20 gallon tank. i dont have step by step pics of how i did mine but i know there are tons of threads and videos out there that will show you.
mine has a small heater/skimmer chamber, then a fuge (DSB+Algae), then baffles, then a return pump chamber.
i would use the biggest tank possible for your sump and make the skimmer chamber much bigger than what i made mine. i can only use a few skimmmers...most being HOB because of the tight space...but i wanted more area for my fuge.