I believe it's very doable to have a 300 pound 20x12 foot boat that would be as durable as any production boat built today. The only thing is it would cost a whole lot more than 17k. The Mastrom 20 comes to mind.

So, it's not durablity you have to worry about it's the pounding the crew would take as the boat decelerates and then takes off again as it goes though the waves ( 6-12 foot sees w/ 3-4 chop on top). This would absolutly wipe the team out. Hell, it's hard enough to stay on the boat now! Plus I'm sure these lightweight monsters would tend to get a little airborne, which again makes staying on the boat a challenge.

Dave