Just a few extra details that I forgot last night, this is the 75qt Coleman Wheeled Xtreme 5 Cooler, which is almost a cube. I picked it out of the other options of it's size because it appears to have the smallest hump of the wheeled varieties, placing the drain lower than most. I wanted a more "cube" style when going larger, just for the compactness in my setup, and have seen a few people mention using them, with others asking for pics etc of their manifolds but rarely anything further, so hope this helps anyone else looking to pull the trigger. I should have some more feedback after I try it out this weekend, but overall the manifold was pretty easy, it measures roughly 9" x 14" and the center outlet is just a T, a 45 elbow, some CPVC and another 45 elbow attached to a CPVC/stainless female coupler, attached to a bulkhead.
As it currently stands, the ball valve, when handle is closed, actually clears the floor below, so you can use the wheels to make it a tippy dump (main reason I wanted a wheeled cooler). However, it JUST fits as it is, so adding any sort of barb, disconnect, etc. will change that. I had to remove the extendable handles in order make it useful for a tippy dump, and the way this sucker is designed, the black piece where the lid hinges has to stay on otherwise it creates an opening on the lid which would let heat out, but this also lets the lid swing further back so it shouldn't be a big deal.
Some thoughts down the road, I'll likely modify it in a way to remove the wheels or at least attach them somehow to keep it stationary and just pivot on that point, but cut an opening on the platform beneath it (or leave some sort of gap) so the valve and any fittings can clear when tipping it. The lid itself feels pretty flimsy so I have my doubts about how well it will hold in the heat, so if that proves to be a problem, I may modify it somehow (insulate it or something) and may even just remove the flips that keep it hinged so it can be removed easily for any reason (not a big fan of it having to swing front, may get in the way when trying to stir the mash, etc).
Anyway, that's the low-down on it so far, I'll report back with more details after it's had it's first use, but let me know if you have any questions, thoughts, suggestions, etc. Cheers!