Welcome to Inliners! Of course any one of your ideas will add performance, but something I'm learning is doing these steps in increments is easier then everything at once unless you've had experience modifying 6's before or have knowledgeable friends at hand. The best advice I've received from Inliners here is to get the 6 to breathe.So maybe a first step should be cleaning up the head and a good header system.
Just my thoughts.
