The KB design is a tad different than the others on the market. More boost is possible with cooler temps generated by the blower drive and a great fuel system/tune. 20 sounds a bit high for my taste, but have seen 18psi on a 96 4.6 Cobra block without destruction. Biist is not evil, detonation is.
Have run his set-up on many Fords. Never any issues with the blower itself. Most of my stuff was adapted one off stuff. With the exception of some 5.0 and 5.8 mustangs.
To get Jim to actually produce the kit he typically needs some encouragement. Drop him some emails and I bet it comes out a whole lot faster. Ask for a group purchase of 10 or so kits and it could be out in 90 days.
I have worked with him before. But for the curious I will stop by and see what the scoop is and give you an update.