Hybrid Prototype (google it if this interests you)
8 ft long, 3 ft wide - Weighs about 50 pounds. Easy build - 2 sheets of plywood, some resin and FG cloth.
You can sit in it or on a bench seat across the gunnels. A dolly cut short and ratchet strapped to it helps lugging it around...your gun, decoys, and lunch go inside the boat.
I had an inner tube with a seat and hated it. I also know a guy who had a truck inner tube with a board tied to it for a seat. He carried that and a paddle around with him everywhere. Worked okay I guess. The little boat is more suited for what you want tho.