June, I would keep the sump and fuge seperate to avoid micro bubles from getting into the fuge and macros from getting into the main tank.
Picture this.... a 10gal tank holding your skimmer + return pump (plus a small feed pump to the fuge) with 3 baffles keeping micro bubles from entering the return pump.
For the fuge lets say a 5 gal tank place above the 10g tank with a bulkhead drilled near the top which will drain back into the sump via 200-300GPH feed pump from the sump.
In a small setup with a small return pump, vinyl tubing will be fine for the connections. If you want things to look a little neater you can use PVC. Take a look on reefcentral. There are plenty of diagrams on DIY sumps.