You're going to have the internet do-gooders tell you to post in the right section or use the search functionality very soon. I'll try to help you as much as possible though:
The equipment exchange on this forum will allow you to post a WANT TO BUY ad for a new stock. You'd do this to get a plastic norinco, USGI fiberglass, or boyd's walnut.
You can get M14Doc to make you a custom composite CQB stock by visiting his dealer thread and then e-mailing him.
There's Mystic Precision who is offering the Archangel m14 stock for $299 but he may be sold out.
Try to look for Troy, Sage, VLtor, and JAE stocks from big importers. These typically run 1k+ so you have to be rich to want one on your m305.
I hope this helps, check out the battle rifle section for more information.