This is one instance where I don't hawk eBay for NOS stuff. Use a modern kit with ethanol friendly parts. Walker is a good brand, Hygrade....IF you can find anyone that still sells them locally. Borg Warner, just any of the big brands will be fine.
I buy from Daytona Carb based on recommendation from Daniel Stern. (slantsixdan) And they know carbs in and out.
They use components that are resistant to modern gas.