Rick -
One of my favorite online stores is McMaster-Carr at
www.mcmaster.com . It's a hardware store and the neatest thing about it is the way its products are organized. I just did a quick search in the Electrical, Wire and Cable sections and found high temperature wire in a variety of sizes and insulations. Their prices are reasonable and they deliver very quickly. If you can't find what you want close to home, I suggest you give McMaster a try.