Off topic regarding a homebuilt boat, but my daughter just returned from a year in Australia (East Coast) and Tasmania. The powerboats she was most impressed by (especially for their rough water performance) were the powercats. This squares with the observations by John Kiley, a yacht designer friend on Cape Cod, who's designed a series of effective sportfishing powercats. (Search for 'benchmark' on yachtworld.com if you're interested in seeing a 36' and 38' sportfishing cat.)
Back on topic, I agree with Ian... but then I almost always do!
“So we beat on, boats against the current, borne back ceaselessly into the past.”