I would recommend these brakes Power Stop K6559 Rear Z23 Evolution Brake Kit with Drilled/Slotted Rotors and Ceramic Brake Pads https://www.amazon.com/dp/B01AGBQZYM/ref=cm_sw_r_cp_apa_i_9l9FCb0XAF7KQ

I've always liked power stop and they've never failed me.

You can get the tool if you want, but it's not necessary, using the old pads and a screwdriver is fine.

Basically, you take off the caliper, and with the old pads still in there, you wedge a screwdriver, against the old pads, and push the piston back.

Another pain free way is to use a c-clamp, also with the old pad in there and some sort of cushion on the outside of the piston.