Actually, I was planning on a board design as well. Trust me, unless you're buying from MegaChess.com (for one of their smaller boards), you won't find a marble board big enough to compensate for the 6" set.
Of course, the design also comes in scalled down sizes of 3.75"and 4.625" tall. Maybe a board will work with these smaller sizes. =)
If I get the money, yes, I would buy it. I currently am playing on a beautiful marble board, but it came from a garage sale years ago. My pieces were glass of crappy quality and they all chipped and got sharp edges and were just junk and I got rid of them. I'm stuck with plastic now that is so cheaply done that they are hollow. Yours would be a great upgrade. =P