I found a seller of a Brompton clone in North America called the Solorock 321. It fits all the requirements you're looking for except that it is not very light. It is a bit heavier even than a six speed C-Line but this bike has all external gears (9-speed) and has the pig-nose and rear rack. All for just $625 USD. Not sure how much shipping is from Canada to your US address, but I'm sure it isn't much. Check it out:

321 Model - SOLOROCK 16" 9 Speed Chromoly Steel Alloy Folding Bike | SoloRock Sports & Appliances

Edward