Looking to replace a Taco 00R-MSF1-IFC? Try the Grundfos 59896341 (Grundfos part number UPS15-58FC) as an alternative. These pumps have the same pump curve and specifications, so the Grundfos will work the same way that your old Taco pump did.
Taco pumps and Grundfos pumps can be found at www.supplyhouse.com