The Hitachi WM-P400GX / WM-P750GX Water Pumps are their top-of-the-line. Unfortunately the manuals are in Thai only.
I have seen many posts on many forums from people trying to find an English language version. I have looked high and low to no avail, but perseverance pays, I knew one must exist somewhere, and, voila, here it is:
Okay, no it's not. There is a note below that says: "You may not post attachments."
If anybody can tell me how to post a 1.25mb PDF, I'll post it here. Otherwise, go get in on ThaiVisa; I posted it there.
Thanks.