In my place we can obtain, only 3 kinds of wood:
Cherry
Beech
Mahogany
We buy it in layers of 20 cm wide 2,60 m long and 1 mm thick (except cherry wood wich has almost 8 meters long…)
to make a good cover board, wich is the best wood for this, and still thinking in “little” weight, which is the best wood for a 9´2" longboard, almost “classic”??
Don’t know much about veneers; But I would say that you should stick with the longest length so that there is no seam. A seam will require matching the grain. Depending on your veneer and grain that could be very easy or impossible. Cherry is nice. If I remember right Beech is lighter in color, so that can be a nice contrast if you can match grains. Others on this site are “wood experts” and I am sure they can set you straight and make the necessary reccomendations. 1mm is nice.
A seam will require matching the grain. Depending on your veneer and grain that could be very easy or impossible.
You can use pinlines or darker wood strips to place between them (V form maybe?)
think practical 
Mahogany has been used for boat building for many years. It’s easy to work, fairly light weight, strong and good grain character. That’s what I’d use.
I think you’ll find that the mahogany will have the straightest grain and darkest, beech the lightest and cherry light but darkens some when finished or laminated if the resin penetrates well, say a thin epoxy. As has been suggested, mixing them will give a traditional appearance. If you cut strips of the 1mm wood and fit them together with a scarph-like joint :
Though I am probably telling you something you know already.
You could try for something like this , where Paul Jensen has mixed fir ( mahogany will be similarly dark) , white and red cedar ( analogous to beech and cherry) to come up with a very nice look.
The weights will all be pretty much the same, at ~>35 lbs/cu ft. Mahogany is the lightest, but not all that much.
hope that’s of some use
doc…
For looks I wood go cherry top and bottom and mahogany rails. w a deep blood red pinline where they meet.
edit sp, “would”
geesh grain on the brain
the opposite would look nice also,
I´m liking it…
But anyone can imagine the total weight of a 9´2" x 22 1/2" by 2 5/8 (or a bit more…), with EPS inside, 4 0z, wood, 40z??
I have one 9´ 2" of Kym Thompson (http://www.watercooledsurf.com/), in wood and she weights a “little” bit, but she floats a lot…