Adderall is a controlled substance (schedule II) in the U.S. and is available only  by prescription.  You can buy it at your local pharmacy with a prescription. Many mail order pharmacies in the U.S. will also sell it with a valid prescription.  Some foreign pharmacies also sell it by mail order. 

Strattera is more widely available than other ADD medications since it is not considered a controlled substance.  Talk with your family doctor as a first step before ordering any prescription medication.  The FDA allows U.S. citizens to order up to a 3 month supply of medications from other countries, but these medications cannot be controlled substances.  These laws are in flux, so this information may have changed by the time you read this. 

More in-depth information on mail order pharmacies is available at pill-bottle.com.