What type of Stucco should I use? Can I just get away with 2 layers of Base Coat stucco?

If using two types of stucco (base/scratch and finishing), how much of each do we need? My kit instructions just say “200 lbs of dry/powdered stucco”.

For the 28" Mattone Cupola, is it as simple as (qty 2) of the 100lb bags of dry stucco?