This is a video that talks about C&C cage supplies and where you can get them in the United States. I also talk about alternate options to coroplast if you can't find any in your area. Here's the list of places where you can find the supplies:

Storage Cubes/Mesh Grids-Target, Walmart, Kmart, Sears

Coroplast/Currogated Plastic Sheets-email or call your local sign shops to see if they have any available

Cable Ties-Look for them in the "Electrical" section of your store. Walmart, Kmart, Target, Home Depot, and even some dollar stores carry them

Here are some other useful links:

Link to sizes of coroplast you would need for the cage size you want-http://www.guineapigcages.com/

Guinea Pig Zone link-http://www.guineapigzone.com/

Feel free to comment if you have any questions. I would be glad to help. Remember, if you don't have any of these stores in your area you can always go to their websites and purchase the items online.