Sinclair Interplanetary sells magnetic torque rods, and can also provide electronics to drive them.  Over the last year a total of 58 flight torquers have been delivered.

Magnetic torquer part numbers and datasheet

Torquer drive electronics part numbers and datasheet

The heritage TD-3-9-1-SPI drive electronics are now being replaced by the new TD-3-28-3 unit, available in a variety of communications options.  This PCB is not internally redundant, but can be packaged two-to-a-box to drive redundant-wound torquers in a fail-safe configuration.