Measuring high currents with toroids
While the inductive PT27312 seems like a good idea, you may look at a simpler solution. A current shunt is simply a very low value resistor. With a simple amplifier or a panel meter you can actively control the current via your SMPS or just monitor it via the panel meter. 

Search for "current shunt 100 amps" and you will find several very low priced options. A word of caution though, some of the low cost panel meters are easily destroyed by hooking up the current shunt to the high side instead of low side of the circuit. 

If you want, you can make your own current shunt, however, calibrating it will require some higher precision equipment than a simple multi meter.