The Mancini kit is just a reproduction '73+ Mopar disk brake set up. It does not use GM calipers, not sure why the tech would tell you that but that kit is 100% reproduction mopar stuff. It is a similar kit to what DoctorDiff sells, but the MBM kit will be 100% offshore parts.
It does not use the same style calipers as the magazine article you linked, so, what they did may not be relevant at all as that's a completely different kit.
As for what it will and will not fit as far as BBP mopar wheels, my suggestion would be to call Cass
@DoctorDiff and ask, because he will know what that kit does and does not fit as far as OE mopar wheels are concerned.
You can also build your kit options with DoctorDiff, so you get the options that you need/want.
10.95" Front Disc Brake Kit (Stage 1)