The best way I found to carry the stuff was to make a simple front tramp. When I camped with a wife and two girls we would carry quite a bit of stuff on my TheMightyHobie18 mag.
I found a mesh tramp half then went the Depot and bought 2 lenghts 1.5" alum. tubing. 1 - 2in. alum. angle. I took the tubing and using a spare tire mounted on my trailer, tweaked the 2 pieces of tubing until it matched the contour of the main beam. Then I cut 4 pieces of the alum. angle about 1 foot long taped them to the inside of the hulls on the shear at about where the tramp would be. Then trimed the ends of the tubing until it would butt up against the inside of the angle. Took the boat to a welder and had him weld the tubing to the angle. I then carpeted the inside of the angle to protect the boat from scratching. The tramp already had grommets along one edge. That was laced to the front to the front tube. I added about 6 grommets to each side and ran large shockcord with plastic hooks attached. The hooks attach to the outside of the shear pulling the sides tight. The rear tube was tied in three places,ends and center to the main beam. I added gromments to the rear of the tramp and laced it to the rear tube. At the front I replaced the the clevis pins at the bridles with shackles. I then ran a continuous line from the center of the front tube to a shackle back to the tube then to the other shackle. I used a clam cleat in-line to tension the whole thing. It very light and takes about 5 min. to rig or remove. We would stack the dry bags and coolers on it leaving the tramp mostly empty. My daughter could lay on it and it supported her. In fact I left it on all the time. I'll see if I can find a pic.
I'm starting to work on one for my M6.0. Its going to be similar to one I saw on the ARC 30.
Mike