Check the classifieds section here. They have pretty much everything.
I always recommend Fuzzies Kingdom (user name Tanya on here) for supplements, organic hay, and hammocks and stuff. They have the best made hammocks and houses I have ever seen, as well as tube covers. They are a bit more expensive than some other places, but they seem to last forever around here.
I agree with Tunes for Tanya's products. I have bought several of her fleece products and are of excellent quality and extremely well done. Her herbs also excellent.
I have purchased from Camphore, Classy Chinchillas, Twilight, Shana, Randy, Forever Feisty Chinchilla Rescue and have been totally satisifed with service and products.
Twilight Chinchillas and AZ Chins for toys. Ronda's Chins and Stacey Wolf for wood. Camphor Chins or Chin Chic for fleece. Tanya for supplements. These are just my favorites but I have bought from many and never been dissatisfied!