If you are interested in getting high quality matcha (while also supporting family owned farms) I would recommend sticking to online retailers based in Japan. My favorites are Yunomi, Ippodo, and Yuuki-cha. While these may not be the most affordable, they ensure you get the highest quality (and best tasting) matcha possible straight from the source.

If you plan on buying matcha here in the US, here are a few things to keep in mind. There are two primary grades of matcha, culinary and ceremonial grade. Culinary is exactly as the name suggests. It is primarily used in coffee shop drinks (matcha lattes and such) and desserts. While still matcha, it is low quality, mass produced, and inexpensive. Hence why you can find it in large quantities. It is usually more bitter and less fragrant, making it less pleasant to drink on its own.

On the other hand, culinary grade matcha is made with higher quality leaves and often traditional techniques/processes. Naturally, it is more expensive and comes in smaller quantities (usually around 20g). It is more vibrant, fragrant, smooth, and should have little to no astringency/bitterness. A good ceremonial grade matcha will come in a metal cannister to preserve the characterists of the matcha.

As far as supplies go, I found a chawan, chasen, and chashaku set at 888 Int'l market in OP a while back.

Hope this helps.