The parts you're looking for have not been made in two decades. While a needle is available from a third-party maker, the spraybar assembly is not. You'd have to locate one through an internet 'swap shop', or from a dealer who sells parts to engine collectors. They usually advertise in small ads in the back of model magazines.

A needle can be obtained from Harry Higley and Sons:

HIGG2200 NVL001 LARGE NEEDLE S15 3000 US$4.95

You can order this through any hobby retailer.