Good news!  I was told today that two balsa logs about 1.5 meters long and about half a meter in diameter should be at my apartment this Thursday.  They will take a couple of months to cure, then I will take them to be cut into sheets.  I will try to post photos, since I doubt many people have seen what balsa looks like except in strips and sheets, so it should be something interesting and educational.

The Latex I asked for will be here sometime early next week.  I will do some tests to see how stretchy it is.  At $15.00US a liter it is less expensive than latex I have seen online, plus there are no import duties, or shipping costs.