The 4.3 compatible SuperSU is already included. No need to flash anything extra unless your particular version of CWM causes an issue. I think for now TWRP is recommended for all 4.3 builds with with root.
That said, what would be the easiest way for me to replace cwm with twrp in 4.3? Goo won't do it. Arrgh. I used twrp for the last year and had just switched to cwm right before flashing 4.3 because of some funny business I experienced with twrp 2.5. I much prefer twrp.