For professional use and AC only the Pearson are the best, in a wide range of types and peak I, someties on epay or at ham fleas.
The TEK are classics and also can be found used but any clampon TEK has a fragile core in the tip, often damaged by a single fall.
Unfortunately the CM noise and self L of the shunt in a 1500 A system will be a huge issue with any shunt, regardless of the diff amp employed. Thus shunts are used mostly if DC responseis required.
The Hall effect devies have mv of output and drift and the ams and Hall device response times seem too slow for this use.
SLAC, CERN, Harwell and otheratomic research facilityes often publish paers on measuremens and may have some tips on such a problem.
We have both Pearson, TEK CT-5 and Yokogawa probes and CTs.
But never had a 1500 A pulse to measure!
Bon Chance,
Jon