Where can I find sumi-e supplies?

I'll be returning to Japan for a couple of weeks next month and I wanted to buy some sumi-e supplies that I didn't bring home last time. My biggest problem is that I don't know what the names of the supplies are in Japanese because my classes were all in English. I already have brushes, ink stone and the ink, so I'm pretty much looking for rice paper, backing paper and perhaps ever the starch glue used for backing.
Does anyone know what these are called and where I can find them? I'll be in Tokyo, Osaka and Kyoto for my trip.
Thank you!

You will need paper, backing paper(or paper pad) and paper weight(as option).

There are several types of paper. You will probably need to purchase "Gasen-shi"(画仙紙), the most popular and cheap.

Backing paper or "Shitajiki"(下敷き), is a felt type mat. Choose a bit large size and white color mat(You will notice a black/blue ink point before trace).

Paper weight or "Bunchin"(文鎮) as option.

The others include dishes(皿) for color pallet, brush washer or "Fude-arai"(筆洗い).

http://suibokugaya.ocnk.net/page/1

You can purchase them at

[Tokyo]
Sekaido Shinjuku head store
http://www.sekaido.co.jp/

[Kyoto]
Gwasendo
http://www.gwasendo.com/

[Osaka]
Sasabe
http://www.sasabegazai.co.jp/

thank you so much! I'll make sure to check those sources you mentioned. The only thing I wanted to add is that by 'backing paper' I actually meant the slightly thicker paper that is glued to the back of the painting so it evens out all the creases and folds.

Thanks again :)

What you are looking for, is like a Backing（Urauchi,裏打ち)paper(youshi,用紙）.

http://www.aisf.or.jp/~jaanus/deta/u/urauchi.htm
http://www.takase.com/LearnJapaneseCalligraphy/ShodoLessons/CD001/S001...