I wish i still had pics of my old 10gal sumps.In any case,your design seems to be fine but i would like to offer a few suggestions.First of all,I would go with your original design,skimmers perform best in a small volume of water with a stable water level and with a direct feed from the tanks overflow.By submerging the plumbing into the skimmer chamber down near the skimmers pump,your skimmer will recieve a higher concentration of organics than if it was just sitting in a large open sump where the overflow from the tank was far away from the skimmers intake.By drilling holes just under,at,and ablove the water surface,the air that is in the plumbing will escape.This will cause alot less turbulence/bubbling in the skimmer chamber.Another idea that i recently used is instead of useing an elbow fitting to direct the water into the sump/skimmer chamber,I used a T fitting.I added a a short length of pipe to the top of the T and left it open thus creating a vent.To prevent salt creep,take some poly-fill(used for stuffing pillows) and stuff the open end of the pipe.I would also advise useing the same baffle configuration for your return pump section.In a small sump like a 10gal,microbubbles can be a problem so IMO/IME its best to have 2 sets of baffles dividing the skimmer section from the return pump section.The last thing that i would recommend and something i couldn't live without is having the return pump section drilled to accomadate a $12 float-valve.Then you can have a gravity fed auto-top-off by merely connecting some tubeing from the back of the float-valve to a 5gal bucket or any other reservoir that can hold top-off water.With a small sump/small return pump area,the water level in that section will drop quickly and you'll find that your gonna be topping off at least 2-3 times a day.This will become a PITA and you will wish you would of spent the extra $25 to do the gravity fed/float-valve top off setup.