Welp...Weiand and Edelbrock for intake manifolds come to mind. Headman and Hooker for exhaust. I remember lots of guys running Mallory magnetos. Good news is Mallory is now making a breakerless racing distributor that looks identical to the old magnetos but works on the same principal.
You may want to contact Floyd Garrett at
www.musclecarmuseum.com He has some out-standing 'W' cars of the 409 flavor. He may have and/or help you track down some era correct after market parts.