How about a panworld 100px-x? It is rated exactly the same as the MD40RLXT.
Here's the Panworld writeup:
"Pan World Magnetic Water Pumps are built by a former chief engineer from Iwaki-Japan. It basically has the same specifications such as flow curves, high head pressure and reliability. It also features seal-free bearings and magnetic drive for trouble-free use. These pumps are quiet and economical, making it a good choice for your system. Plus, it comes with a power cord unlike Iwaki pumps."
PM me for details.