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:
Hitachi WM-P400_750GX_En.pdf
Please post it on other forums of which you may be members. Thanks.