Sufaat used his company called Green Laboratory Medicine to buy items useful to Al Qaeda. (Green symbolizes "Islam" and Prophet Mohammed's holy war).
It is interesting the anthrax letters were addressed from the "Greendale School".
Some further relevant excerpts...
...Padilla, the former Broward man suspected of plotting to explode a ''dirty bomb'' to spread radiation in the United States, also worshipped at another Broward County mosque, Masjid Al-Iman, in Fort Lauderdale. That mosque was across the street from Franklin Park... , even though several of (the Sept. 11 hijackers) had lived in Broward County... Mohammed Atta lived 11 miles away from this mosque across from Franklin Park, where these members of the Egyptian Islamic Group worshiped... correspondence on Zawahiri's computer shows Zawahiri uses "school" as code for "Al Qaeda."... "Dale" means "river valley." Greendale refers to green river valley -- i.e., Cairo's Egyptian Islamic Jihad or the Islamic Group. The sender is announcing that he is of either Egyptian Islamic Jihad, Egyptian Islamic Group or Jihad-al Qaeda, which is actually the full name of the group after the 1998 merger of the Egyptian Islamic Jihad and al Qaeda.
The above link leads to a treasure trove of information.