What sail range would you anticipate this new board to cover ? Seems like 15 kts is a typical max (?) but what about the other end of the scale, that will influence the volume/size/model quite a bit and ultimately the biiger you go in size/bootom end the more restricted you will be if/when the top end days come along.
One thing to have agood look at for 2008 is the new GO range, which takes in the very real advantage of using the new Futura shapes (directly) but with stronger construction and EVA deck - these things might not look so "pro" to some people, but in and advancing intermediate, the added durability can be a real advantage in some cases.
Usually, these GO boards maintain a really excellent resale rate too, so taking a mid term step on something like that on the way to the lighter construction in a season or so can be a good option.
Let us know a little more on the sail range and we'll suggest more accurately.
Cheers ~ Ian