Yes, I have seen them before and the sinseh is quite good. They have both herbs for brewing and bottle form. I bought a pot from them for brewing medicine and it saves me a lot of hassle on brewing.
Check out this tcm shop at toa payoh lor 8. It's a row of shophouse next to e lor 8 market. The store sign is red in colour next to melben. Can't rem the name. The sinseh there is really v good. Went there twice.. Helped me recover v fast