As you have known the best brushes are those made of real animal hairs. If you're at all squeamish about or ideologically opposed to the sources of natural hair, then synthetic is the the to go. Here are two specialty brushes that are made of 100% synthetic hair for Chinese paintings or Sumi-e:
1) Synthetic "white cloud" brush that simulates sheep hair (NO animal hair is used) with a perfect pointed tip. Bristle length 1-2/8" and 1/4" diameter. Natural Bamboo handle total brush length 9". This "white clouds" brush is good for painting glowers and leaves, birds and animals etc.
2) A "bamboo and orchid" brush that simulates wolf hair(Again, NO animal hair is used): bristle length 1-3/8", 3/8" Diameter, total length 10-2/8". This "Orchid and Bamboo" brush is used for calligraphic strokes such as bamboo and orchid.
This set of two brushes are perfect for beginners. To paint roses, for example, use the white brush to do the flowers, the brown brush for the leaves and canes, as well as the veins and thorns. You can also use them for calligraphy practice.