Good luck - Partzilla is a reseller - they will order the part and then when informed by the distributor that it is NLA they will eventually (within a month anyway) issue a refund for the unavailable part.
You can re-engineer the unit with a fuse box, 5 wire rec/reg, change the temp sensor from a thyristor to a switch to turn on the fan and if you want a hot indication, get creative and install a second temperature switch to turn the light on. You may have to install some plumbing to be able to install two thermo sensors or retro fit a radiator with a fan switch port and install the fan switch in the radiator and use the thermo sensor hole in head for a hot lamp switch..
Multi function electronic control units lower production cost and decrease assembly time, but are subject to discontinuation when the vehicle is past it's projected economic life. Over 10 years old it's time to dispose of and replace with a newer more complicated, technologically advanced, higher priced, more costly to maintain, but better vehicle.