I've sees a milled 40B - I own one

The 40B is an excellent shooter out of the box, However... it is an amazing shooter once once you install the Cajun Pro kit!
I expect the 40P with the Cajun Pro kit will also be a fantastic shooter.
BTW, the 13lbs hammer spring will noticeable improve the double action trigger pull weight - it won't do much for the single action though. Still, not a bad idea to do.