USGI components can be difficult to find. Try treelinem14.com or shop.m14-parts.com. In Canada Armtac has a good selection of M14 parts from Sadlack, LRB and others.
Why do you want to replace yur bolt? Do you believe there is something wrong with your Norc bolt or do you believe that your headspace is excessive, or have other reasons? Just curious given that it's a new rifle.
USGI guide rod and spring are a waste of cash in my view. If you want US spec. components, buy from SEI or Sadlack - don't think you'll see any difference.
Welcome to the club.