MJ, Welcome to the forum!
Have you had underwater vegetation problems in the past? I was wondering why the grass carp in a new pond. Advice? Don't stock the crappies. Buy The Pond Boss book Raising Trophy Bass. While a 4#-6# LMB isn't a trohpy in your eyes, it is to some people and the principles in the book will help you get to your goals.
What other fish are you planning on stocking in the pond?