So what is the best way of telling if an amp is high currentIts also a good idea to know what is meant by 'high current'. Many manufacturers specify a current value independently of the output power of the amp, but current can't exist without voltage, and voltage and current together are power. Quite often these 'current' ratings are actually the amount of current present when the power supply is short-circuited and don't represent the output power of the amp at all.
If you are concerned about the amp being able to drive a low impedance load, here are some additional things to keep in mind. First, what is needed is that the amp can act as a 'voltage source' into that load. This simply means that its output voltage will not be affected by the load impedance. Second, you really want to think about what it means to make an amplifier work hard for a living! All amps make more distortion into more difficult loads and that distortion is audible as brightness and harshness. IOW if your goal is high quality audio, you might want to consider working with a speaker is easier to drive, even if the amp you have in mind can be used for welding (perhaps, **especially** if your amp can be used for welding...). Amps that are working hard generally don't sound nearly as good as they could otherwise!