So I'm sure there are a few other crew out there who are cutting foam in the backyard and want to share some ideas and experiences. Here are a couple of mine to get it started.
6'6 single pin and a 5'5 simmons

I'm thinking of building a kite specific 5'6" surfboard using "paulownia" wood. There are a few surfboard companies using this light hardwood, so I'm not completely mad. Good thing is, it's waterproof raw and doesn't need fibreglass to finish it. A coat of epoxy resin will do. The forums say it's nearly as light as foam/fibreglass boards as well.

Does anyone have any experience with this material or am I thinking too far outside the square?