What's your budget? You can get a "small footprint" model as some skimmers now have the pump inside them in the bottom. Off the top of my head I'm thinking that a Bubble Magus NAC6 would be fairly compact and allow you some room for baffles and a refugium. It does prefer deeper water (9.5"-11") so you'd cut baffles at maybe 10", then another at 9" and one that is 2" shorter than the height of the sump. This last one would be the divider between the 10" and 9" baffles, and you put it so that it's 1" above the bottom and 1" below the top rim.
The important thing is to get all the equipment before you go start installing baffles, don't want to get the sump built only to find that something doesn't fit.
Is the 72 reef ready? Which side of the tank is the drain on? For the fuge, are you wanting a deep sand bed, or just a place for chaeto and a light? For the fuge, I would get the glass cut to be 2" less than the top rim of the tank, then use a strip of eggcrate to fill the top 2", this will act as a strainer to keep the chaeto in that section. You could of course get slots cut in the glass, but IMO, the eggcrate is easier.
You'll probably want the fuge on one side of the sump, and the skimmer section on the other side, with the return pump chamber in the middle. Get a return pump a little bigger than you need, and you can T off of that to feed the fuge and throttle it back to get the overflow rate you want. I'd figure somewhere around a Mag 7 would be good for you.
