Mil gracias, adibac! Your post nudged me to check out Aircraft Spruce and I discovered that they are located just a 30min. drive away so I hopped in the car and zipped on over and now have my supplies in my hot little hands with no waiting and no shipping charges (and no hazmat charges)! Wahoo! Now let's just see if I manage to get them back to Japan. [] Here's what I bought:

1 quart non-taughtening nitrate
1 quart non-taughtening butyrate
1 quart taughtening butyrate
nitrate thinner
butyrate thinner

Cheaper than ordering from SIG. That should just about do me!