perhaps you need a current monitor and a microcontroller, so that the micro can allow the overcurrent to be drawn for just long enough for you to make your observations.....your power supply will need to be rated for that output voltage and current, though if not having overcurrent for a long time, then you wont need to have the heatsinks etc made to withstand it for long periods.
Mains transformers (50hz) are known for being able to supply current well above their nominal for intervals and not have a problem......when i did a SMPS for a guitar amp they were moaning that mains transformers were great for their useage because they can handle the average power throughput fine and also handle the severe overpower transients that get pulled.
Also, buyers of guitar amps like them to be big and heavy!...they think its a mark of quality for their heavy metal use.