I will start with pointing you to the search function on the left hand side of the screen, and the tech section. Tons of datto owners have done or are doing brake up grades and there is a SH#T LOAD of info in previous posts. The simpelest up grade is 120y struts and discs for the front. They bolt straight in (sometimes). Are you meaning using the R31 rear stuff for the front or rear of your car. What is your car currently running. The more info you can jam in your posts the easier it is for the forum members to help you out.
Also let us know where you live, someone near by may be able to stop in and give you a hand or advice.
My brake upgrade for my 1200 ute is 120y front struts, custom adaptor plates and nissan silvia callipers and rotors on the front and rebuilt STD rear drum brakes, stops like an absolute WEAPON
You will be able to use plenty of bits off the R31 and will be able to sell off stuff as well