I agree with Wyogal, but will take this one step further - Do NOT use ANY mold that does not specifically say it is for molding at extreme heat. If you used a plastic mold that is made for say, chocolate, which melts at a much lower temperature, you will just go right through the mold instantly causing a mess and great danger to yourself.
I work with hot sugar a lot in my work and you have to be extremely careful with it. If you can find some molds online at the sites Wyogal mentioned, I would order them. Even though it will cost more for shipping, etc., it is worth it in the end.