My fuge is the same setup but with the fuge much deeper, but that was to get more depth (thus volume) as I have the width of it at only about 6 inches. If you put the fuge in the middle it will be lower, but make it as long (in direction of water flow) as you can.
Remember that by having the fuge water sourced from the T off the return you can control the flow through this chamber. When in the middle, it will get the full flow of the water cycling through the sump.
In the baffle section I made the first section a bit wider and put an egg crate shelf in there. This way if I want to put a bag of media or frag plugs I just lay it on top. make sure the last baffle going into the return section is a bit lower than the first baffle from the skimmer section. This will ensure good flow.