Just do what I did. Cut a small piece from each different size and go to the local parts store and size em up. Don't forget all the little hard plastic elbows and connectors too.
I just made my own last weekend for the GN. New billet vacuum block too. Came out looking like crap I would say. Should have left the old hoses in their at least they looked good.
Someone like Kirban should hit GM up for a bulk order of those factory hoses if still available.
I like the GM writing and exact lengths and properly cut ends on them.