There are SO many great brake kits out there now, I would no longer deal with the Maxima/240sx caliper options. My experience with buying Rockauto calipers was so disappointing that I said never again. Ebrake cable attaching is a nightmare at best.
The BEST experience with rear disk brake kits lately is with DPRacing, though admittedly for 510.
Quality of brackets, outstanding. Quality of Ebrake adaption cable etc was nothing short of astoundingly good. They list kits for Z and 510 with plenty of options. They were all based on separate brake and ebrake calipers, all from Wilwood.
Just my two cents.
This is some examples. They feature kits for small wheels too, front and rear. I think I have the 401-9520 rear kit for 13” wheels. They do fit 14” ZX alloys, but for 13, would need aftermarket open barrel wheels, but they would fit