Call the store on this website to find out who supplied the original mast and boom for the 2011 Hunter 45 D. Then contact the mast maker to get a replacement quote. The folks on this website can also spec and deliver the sails (fromDoyle) and rigging. A local sailmaker and rigger could do the same once you know the specs for the mast and boom.
This SBO team here is certainly the best current source of expertise on the Hunter line. And they will be glad to help you.