Matcha is just a special type of processing of standard green tea. The leaves come from the regular tea plant, Camellia sinensis, but it is their growing conditions (more shade than normal) and their specialized harvesting and processing that results in the matcha powder.

Tea plant, Camellia sinensis, is not hard to locate or grow in climate-suitable areas. If you are able to grow regular flowering camellias well, then you can grow tea camellias also. I would purchase already established, potted shrubs rather than attempt to grow from seed - it would take years before a seed grown plant was ready to harvest.

Here is a website that sells already established plants: http://www.camforest.com/Camellia_sinensis_s/34.htm

Most of them require zone 7 and warmer however, so if you live in a colder climate than that it would need to be grown in some sort of greenhouse situation.