Here are some various Taobao storefronts that sell doll customizing supplies!
Tata's Paradise: basically everything doll--wigs, eyes, clothes, craft tools, and props
Silkgirl Dolls: clothes (also sells a super cute carry bag)
To shop on Taobao, you must use a shopping service. I recommend Spreenow, although your mileage may vary.
If you have any questions about shopping with Taobao or using a shopping service, please let me know.