I was looking for high temperature corrugated tubing to repair a damaged section of harness and stumbled across this site.
http://www.wiringproducts.com/They had all sizes of the corrugated tubing I was looking for. They also have relays, fuses and fuseholders, wire, harness connectors, and even ECM pins, for people who are interested in building or repairing harnesses. (7730 folks?)
Their engine connector/pigtail assemblies are hellishly expensive, but it might be useful if you can't find what you need elsewhere. (Rockauto is also a good source for connectors if you know what you're looking for. Much less expensive.)