Re: carbureted 1000 swap ....
I doubt the SRAD carbs would fit since the spacing is different. IE, the 1000 motor is not as wide.
With that said, I think you are going to open a can of worms with trying to fit 750 carbs onto a 1K motor. The jetting will be out and the work to get it back into the correct tune is going to take a lot (or a good chunk of money on the dyno).
My guess is that you will still need the ECU from the 1K motor as it has all the timing and temp sensors that would be needed to make this motor run correct.
At that point, you might as well spend a bit more (likely less then you would on the dyno) and just put the FI bodies on it, call it done. No extra tuning time and you have a LOT more power then you do now.
99 GSXR750, yosh full race pipe, TRE, Tail light int., 180 rear tire, Almost Illegal Racing suspension, -1 front +3 rear sprocket, flush mount turn siganls, cut fender, 55,000+ miles!!!, Brembo Radial master, 4 pot brakes, balanced crank