That looks something like it, but it's missing the bottom baffle, which is needed in the in-tank application. I could probably just add the in-line mixer between the injector and existing 120-gallon steel tank, but I like the bottom-drain blowdown feature of their tank. The steel tank's drain is above the bottom, and not very effective in blowing out all the residue.
Update: It turns out that the tank I've got IS the tank we're talking about, with the swirly thing hidden inside the tube. I'll let you know what I think about it after I've accumulated some experience with it. For a couple hundred bucks you can add a timed valve on the bottom drain to automatically clean out the accumulated crud.