My tank is not as long or wide as yours, but it is as deep. 36x18x24. My LFS, one of the best around, recommended I go with the A360NE rather than the WE because of the depth. To figure out how high to hang them for best coverage and least light spill he said to use painter's tape to mark the tank exactly one third of the way front to back, then in half the length of the tank. That was for centering them. Then, turn on the light and raise it above the tank until the cone of light was at the waterline. For us that was about 8" up. For the WEs it would be different. I wasn't 100% sure that the NEs would be the right choice but the LFS said if I wasn't happy with them he'd swap them for the WEs. That's how confident he was.

Their positioning means I have overlap in the middle for things that like a lot of light, and dimmer but still bright at the edges all the way down to the sandbed.
The AP700 wasn't out when I bought my lights but I think I would have gone with the 360s anyway; they're very small and it's very easy to hang them from DIY EMT mounts. Two pucks next to each other would have been a waste on a tank my size; it would be harder to get the right spread.
I absolutely love my Kessils. I know some people are convinced that all LEDs are worthless but I have been running these for a year now and had good success. Some of my SPS are slow growers but others are taking over my tank. I even have a stylo and a monti cap about 18" and 20" down in the tank and they seem quite happy. An orange digitata about 16" below the waterline is going nuts. Photosynthetic gorgonians are growing like weeds. SPS at the top of the tank (I have a rock wall) are doing great. One of my wild colonies is starting to peek above the waterline when my return is off.
I have the Kessils hooked up to my Apex and run a 14 hour light cycle from 8AM to 10PM, with a couple of hours at either end at very low percentages and peaking at about 80% intensity for a few hours in the middle (ramping up and down).
And best of all, the cats can't jump on them.

That was one of the deciding factors too!