All good
That's right Only the fronts are larger.
I am using DBA Rotors at the moment.
Many will suggest RDA Rotors and EBC Brake Pads.
Project MU is worth taking a look for Rotors and Brake Pads.
http://www.project-mu.com.au/en/
http://www.dba.com.au/
http://rdabrakes.com.au/index.php/products.html
To get the calipers, either search the For Sale Thread on SAU, ask Aaron from Import Monster (SAU Trader) or give Nissan the Part Number to see if they can order it in for you.
Don't bother with 2nd hand rotors and pads, they are priced quiet well for a brand new item.
With 2nd calipers, get your mechanic to recondition them, it won't cost that much.