Sorry I missed out on this one. In case you do not mind going over to the Hong Kong side, I have a few teashops to recommend. They are all in Sheung Wan, quite near the MTR station:
嶢陽茶行, 林奇苑茶行, 顏奇香茶莊 all on or near 文咸東街 (Bonham Strand East). The second one is most recommendable for their wider selections.
I hope if you have explore shops in Zhongshan, you have got some quality selections. Normally shops where tourists have access in China are really not too reliable, but there always are exceptions. I do not personally know of any there though. Have just seen ridiculous ones.
Good luck shopping!
