What goodies do I need to build a Fast slant 6

I've done several Slant engines.Milling the head usually around $100. One was cut .100 and another .125. Now this depends on how much lift your cam is but usually never a problem using stock pistons that are way down in the whole.
Years ago a well known Slant racer Mike Jeffery said to use the 3-100 method.
.100 off the head .100 off the block and .100 over bore for a good starting point.