Not sure what break booster I need?

I'm looking for power brake booster for my 70 Cuda..I'm not sure what part number I need or where to get one?
Thanks for any help!

A surprise, but your local parts store is a good place to start. Most OE rebuilt boosters are available in a few days from Autozone and probably others. You can check first on line. That's where I got one for a '70 Challenger.

Would the booster come with the rod that connects to the pedal assembly?

yes