One of the best renowned naval architects for small craft is Jay Benford, and one of his most intriguing designs (in my opinion) is the "ferry yacht": Essentially a houseboat built in the style of harbor ferries, resulting in a non-boxy houseboat looking like it "belonged on the water":
http://www.benford.us/pdf/FerryYachts.pdfThinking of how one of these designes might look "paddlerized" as fictitious sternwheeler, I have just built a tiny very-quick and very-dirty paper model. I know it's coarse and the hull is bent, but I simply wanted to check the proportions: Not so bad, I must say.
Moritz