Cleanout is a good idea. When you come out of the wall, the first fitting you need is a wye. The wye will act as a cleanout and a 45 degree fitting. Point to 45 degree branch towards the center of the sink compartment you will have your trap on. Directly out the end of the wye, install a street (fitting) cleanout plug. You will need a trap adapter on the end of the pipe coming out of the branch of the wye. Then install a trap. You will need a continous waste kit and 2 basket strainers. Buy tubular pvc 1-1/2 trap and continous waste.