This place sells seeds but they are sold out right now:
http://seedrack.com/indiv/camellia_sinensis.html
Here is another one:
http://www.seedman.com/limited.htm#263
From what I have read they are a bit hard to grow from seed anyway, you might have better luck with plants:
http://www.camforest.com/index.php?main ... cPath=1_11