Brian,
Weber no longer sells parts for NG to Propane conversions. Liability issues, blah, blah, blah.
What you need to do is find the comparable propane model and look up the part numbers.
(Weber has parts schematixcs on their website.) Then you can order them from an aftermarket parts supplier. Or, maybe someone wants to convert to NG and is willing to make a trade.
Good luck and congrats on your new grill!
AJ