Yes, I do, Two places.

First EBay. Look for kapok pillow stuffing.

Second is found in my Internet Sites for Martinis, Related Material and Subjects . There is is a listing for a supplier who will sell kapok in bulk. Scroll down to wads and fillers and look for Kapok - http://www.atrim.com/Page11.html

Be forewarned a 10 lb bale is a lot of kapok. I use 7 grs in my Martini NfB loads and a bale is enough for 10,000 rounds