[railroad]

You can shop on your own and find everything through Summit Racing. This might leave you scrounging for nuts and bolts, a few trial fits and returns. Not a big issue for most builders.
Next choice will be Mike Forte. Tell him what you want to do and he will package it up for you.
You can run a single plane manifold with throttle body fuel injection and have a smooth idling engine.
The fuel injection is not dependent on vacuum signal to supply a consistent fuel supply.
Good luck, Really like the engine!