How to spot a high current amps?

If the power rating doubles when the resistance drops from 8 ohm to 4 ohm, that's a good sign.
Many companies will offer current ratings when they are high because it's a good sales pitch.
The instataneous current is also important. Newer amps seem to use a bank of small cap's vs 2 big ones. They supposedly recharge quicker giving better transients as well. Since most musical peaks are very quick, the speed or slew rate of an amp can be just as important as steady state current rating.
Disclaimer: I'm only repeating what I've read.

The LFD Mistral SE has no current limiting circuitry. It puts out 75 wpc. Does this mean it's a high current amp? I don't know. To me, if it was a true high current amp it should be able to drive <1 ohm Apogee ribbons and the only limitation would be maximum loudness based on the rated 75 wpc.
Coreymccann there really is no way to know all the facts from a spec sheet. Even if you could find out the amp rating, there are many other problems which you'll never know about. For example, many amps produce high order harmonic frequency distortions which can be incredibly unpleasant. I spoke with a top U.S. amp designer and he mentioned something about thermal stability or intermodulation (Aball is the expert on this stuff) which isn't even measureable but can be audible.
Another way to get high current is with a tube input stage because tubes can handle much higher current peaks than transistors.
I understand your problem because I am having the same problem. You could spend $5,000 trying out all the $2,000 amps out there to find the one that is right for you. So we all have to live in our own fantasy world to some extent and figure what we own is pretty good (or good enough). Or else go broke trying everything in existance.