Upgrades to improve braking

Would the 11.75 rotors and 2.75 calipers be a better fit with the 1.031

1-1/32" = 1.031", just what I had too.
Your braking will improve if you install a larger rotor and larger diameter brake caliper.
But if your car is now similar to my setup, it will still not be a 'perfect' match. But then again; if your car has always been a manual brake car, it will probably have a higher(better) brake pedal ratio, giving a bit more leverage to the MC, so you might be good.

But it's easier/cheaper to change a MC then it's to change rotors and calipers.