What Pitman arm etc do I need for this setup?...

All depends on the centerlink, if its the original one you need to use a 72 and older steering box and a 68-72 pitman arm. The 68-72 centerlink will have the nuts for the pitman and idler arms facing the engine, 73 and newer has them facing the ground. The idler arm doesn't need to be changed unless you're changing the centerlink.