Hey Brenda, thanks for the comment. It really depends on what you are trying do with the sculpture and how big. Is it going to be a permanent exterior piece or other. There are a lot of different coatings and mixtures, expensive and cheaper but can sometimes produce the same results. Is your profile picture some of your work?
Derick
Tiny Town Studios, LLC
Panama City, FL

Brenda you can use a pre-mix from companies like styro-crete. You can use the base coat which comes in a 5 gal. bucket for about $35.00 and mix 1 bag of portland cement with it which will then give you 10 gals. mix. Use a texture hopper gun and spray your mix on. Quick and easy, let dry, done.

Brenda, you should be able to find from them a local supplier in your area. Most companies who sell stucco finishes will have what you need. Acrocryle is another acrylic mix that is good.