Can't help on part numbers, but almost any Mustang supply place should have the tall fitting. Even if it's not a Mustang, they almost all have them in stock. Might try NPD, Mustangs Plus, Mustangs Unlimited or any one of 2 dozen other places out there. Finding the small stuff in local parts stores is getting to be nearly impossible anymore. After all, it's been 36 years since the engine was produced.
As for intake gaskets, I've gotten away from leak prone Felpro Print-O-Seals and gone to Mr Gasket. Part # would depend on style of head/intake port.