SiliMed, a company based in Texas, does manufacture 1000cc rated implants. However, Silimed implants of any size are only approved by the FDA under a special evaluation program. This means that they can only be obtained through a plastic surgeon who is participating in their evaluation program, which explains why 98% of US plastic surgeons don't advertise the fact that these implants exist. The 1000cc model is available on special order, but is not listed with their "catalog sizes". See
http://www.silimed.com for more info. If I'm not mistaken, Christine Allure has these special order 1000cc implants, overfilled to 1200cc .
The Polypropylene String which comprises my own and Chelsea's string implants came from a differerent US company which manufactures Prolene Suture String. It's literally just flexible plastic string about 1/16" in diameter! You simply keep pulling it off the spool until you have the desired amount, submerge it in a big stainless steel "pot" filled with antiseptic solution, then take it out while wearing surgical gloves and stick it inside the breast!