I just have regular vinyl. The factory Impala SS emblem is also a sticker, but it's a different kind of stuff than what almost anyone will be able to do. It's kind of a neat material. You can get raised stuff from places that do logos for football helmets and stuff like that, but it's raised via a hardened clear liquid - which is there to protect the actual sticker, and it's typically raised alot more than the stock emblem.
I'm not trying to discourage you. Just trying to share what little I know about raised emblems, etc - and please know that if I had a source for you to get exactly what you were after, I'd link you to it in a second. Please share if you do fins a place too.