Where to buy cable sleeve and heat shrink in USA

I would like to purchase some expandable cable sleeve and heat shrink for a diy cable project. Looking for a USA dealer if possible. Also, if my cables are 3/8" what size sleeving and heat shrink should I get.
Thanks in advance
home depot
Fry's Electronics
Try parts-express.com
Page two of this catalog: (http://www.percyaudio.com/Catalog.pdf) Michael will also provide any necessary guidance, to ensure the best results are obtained.
Thanks to all
You've given me some options..greatly appreciated
Also check out www.heatshrink.com.
They have a very comprehensive catalog.
cryo-parts.com & vhaudio.com are two more sources you could try.
Thanks for all your help, I've placed an order.