Hi PocketGoose,
The sump layout I kept very simple. I just used a smaller (I think 6 gallon) tank. I knew my drain down to the sump was going to be on one end of the tank (peninsula style) and really all I needed was to put the return on the opposite end, so I would get some flow across the live rock in between. I never planned on running a skimmer or any other chemical filtration, so I didn't need any additional chambers or anything. The filter sock holder was bought online and I just made sure it was the right size to fit in the sump and to hold the sock. The closed loop, has worked out well and I have no regrets about going that route instead of pumps (no pumps to ever clean and one less obstruction in the tank for a cleaner look). It's going on 3 years now and working well. If I were to make any changes at all I probably would have drilled the returns closer to each end than I did (just for scaping purposes). As long as the intake drain is high enough it will never suck anything in to create issues. Even if it was too low that could be remedied by just putting a prefilter sponge over the intake that you could easily rinse once a week I would think. The switch to the Vectra has been fantastic. I just set it to ramp up and down like I would the same way as if I were using vortech's. Hope I answered all your questions.