I don't use Kessils, but I will offer since nobody else is. Take this for what is is worth... next to nothing. You are probably not getting much response since not a lot of reefers use Kessils over larger tanks. For me, Kessil is a small tank or nano type of light. The output is low and you need a lot of them to cover a larger area. I also do not care for Kessils over SPS, but this is my own opinion and many disagree... the so-so coloration and shadowing are not for me.
For mixed reef with some SPS and a clam in the sand, you might need 6 or 8 a360s along with 4x T5s. You could up the T5 count to 8 and then use the Kessils to mix in some color to your liking, but a pair of 360s are not going to be able to light a 36x48 area... even a 250w Halide (which is a LOT more power and output) would struggle with 36" on the ends.
It might be ok to not light the front and rear as much if you don't have much corals there. You could light a 24x48 inch area in the center and save some resource. However, even expecting a single 360 to light a 24x24 area is not wise. Some of the people who do use them over larger tanks have one per foot.
For reference, the only 36" wide tank that I know (36x60) has a pair of 6 bulb ATIs with Orphek reef bars in the middle and on each ends. He gets good PAR out of it and great color. He does like to light the whole 36" area, though.
