I'm not sure what you mean by "need optics"--the main lens? If so, then you don't really have a telescope. If you mean the diagonal or eyepieces, there are many sources.
Apogeeinc.com sells surplus and new parts of many types (including some main lenses, if you need that). Astronomics.com , Shutan.com , Scopetronix.com , and Telescope.com are vendors who have given me good service for eyepieces, Barlows, diagonals, and various accessories.

Dan Johnson