Expect to pay big money for good parts. Don't be one of THOSE GUYS bragging that you got an SS for cheap and then are flabbergasted that a new leather interior is $1000. Lower dash $300, door panels $250 each, and so on. And make sure what you have is actually WORTH restoring, or that you WANT to go on the journey.
I talked to a guy at a car show that had restored a 1969 Impala SS convertible. He knew every nut and bolt on the car and told me about all the special parts on it. I asked him how much he had into it, and he said $40k. Just keep that in mind.