If you want the best CNC ported heads out there, go talk to Chapman. They are an example of CNC porting at it's best.
Chapman did one set of my W-9s.... plus I sent them a broken W-9 they ported to see if it could be repaired, it was beyond help... they duplicated my one to a tee.... I still touched up the machining lines, they are the ones I picked up 2 cfm for just a short bit of time