So I read that you've done some research on this subject. My knowledge is only that of normally aspirated machinery. But, in case you haven't seen these here they are: (this one on a 93-95 platform)
SR Archive: Team Mr. Honda CBR900RR Turbo - UFO '1996 | Sport Rider
And I found these guys, kits are long gone, but the info sounds cool:
Honda CBR900RR Fireblade Turbo
I know you asked what sensors and things you would need, and I'll assume you would at least need an MAP, IAT, TPS (96-99 have one), a programmable ECU ($$$), Cam position sensor, Crank position sensor, etc.
Now, if you really wanted to experiment and make a Frankenstein of sorts, in 2002 Honda made the CB900F, or 919. It was a 3rd generation 919cc 98-99 DE-TUNED CBR engine that Honda made WITH FUEL INJECTION. I would imagine most of the hard parts would work between the models up to a point. But it is something to consider.
The power commander won't replace the ECU, as far as I know it compliments the ECU. The OEM ECU for a 96-99 RR however will probably be useless here. You would need some aftermarket unit. I have no experience with that, just throwing it out there for thought.
The pistons from a 929 IMO would not work, the valve angle, valve diameter, and skirt length are all too different.
I toyed with the idea of using a full CB900F set up for a track build a few years ago, but bailed on it just knowing the motor was detuned. It would probably work ok, I just never got the ball rolling.
You're probably better off building the KZ, and keeping the 900 as it is, a canyon carver.
With whatever you decide, if you make the 900 a turbo, we would love to see the build documented in a thread here.