Yup, the Cuda' did have both options back then. Vinyl top I believe, but darn those things were gorgeous and they're fetching a real hefty price.
I'm not too sure if they'll do a hard-top convertible though as that's more weight to add, and I'm pretty sure it's going to be heavy enough already.
But these are already heavy cars and are the most ideal to get a hard top, it's only when you get into smaller segments of sports cars that it shouldn't happen. Something along the lines of a FRS/BRZ. To pay homage to the past Cuda they should at least have some open top with a hard roof, even if its a T-Top or Targa.