What all do i need to take to machine shop?

whatever crank you go with-- stock or stroker, make sure that it is compatible with your transmission of choice. drilled for pilot if manual, correct register for torque converter.

re: power/400hp goal. i don't see much of a problem achieving that goal in that it's <1.25hp/ci

you'll want compression in at least the 9~9.5:1 range, a cam with a modern profile that has lift in the high 400's and a reasonable amount of duration, probably in the low 280's. top that with a dual plane and a 750.

on the heads, i know that 906's will support 400hp but it comes down to how much you want to invest when you have the option of aluminum units that would be more cost effective and a better piece all around. at minimum you'd want a bowl blend with a port match, matched springs and a good valve job. hardened seats are another consideration; you needs 'em, so if you don't has, add that to the list.

obviously electronic ignition. i'd sell along those manifolds and rock the headers.