Buckwheat is a plant similar to cereals, which produces quite a tasty edible seed. My 3year old actually loves it cooked like rice.
Don`t think you can buy the hulls here.
In Germany, spelt hull cushions are very popular for the same reasons. Hildegard von Bingen, a famous medieval healer, promoted the healing properties of spelt, an ancestor of modern wheat.
Maybe someone can bring it for you from Germany.
If you search the net, you could look for `Dinkel` and `Kissen`, for spelt and pillow.
Should definitely cost less than 200 SGD....!