Minerrick1, the M2 technology sounds cool but from what I can tell it will give a rough indication of potential gold-bearing areas. It would be cool for broad area reconnaissance if it's cost-effective. I'm going to read up on it some more, it's always cool to hear about new technologies.
I was really skeptical of the seismic system when I first heard about it. I didn't even think it was possible at first, then as I did more research it sounded really good. Now we have the system and it's awesome.
So what did you guys settle on in the end? There's no known technology that will actually show you where gold is and the depth other than actual drilling. Geophysical techniques such as magnetometry, IP, and EM can help you hone in on source rocks that may or may not contain gold. But to my knowledge, nothing can actually see gold in any meaningful way, let alone the depth.