If you live in Canada then you should check out flowertown chinchillas, their owners karen and dave and their website
http://www.chinchilla.ca/index.php
their supplies are most likely cheaper than petstores and they can guide you through your shopping.
most buys :
Food, I use Mazuri but I think Oxbow is good too and some other brands.
Hay, I`ve heard some bad things about Kaytee hay but then again it`s your choice. Feed your chin Timothy hay as the main hay and some others as treats
Bedding, I use aspen but I think you can use carefresh as well though I`ve never tried it. Just never use cedar and scented bedding. (or bedding that isn`t for chinchillas)
Some people also use fleece but I don`t know anything about that.
Dust for their bath, I heard that blue cloud is really good.
wood chews and a ka-bob to put them in
For their cage you need a lot of places for them to jump around so ledges are good, if your cage is big enough you could get some tunnels, tubes, and hammocks.
If you can`t take you chin out everyday for at least half an hour then you should get a wheel. (I`ve heard the best ones out there is the ChinSpin and the flying saucer. The metal kind.)
You also need some sort of hiding house that`s made of wood.
You need a good water bottle that doesn`t leak (obviously)
A dish/bowl for the food that can clamp on to the wire of the cage so it doesn`t fall over or a really heavy ceremic dish.
Lastly (that I can think of) you need lots of toys for them otherwise they`ll get bored and may develop some issues.
Good luck