Environmental Potentials whole house surge protection, can I get your opinions?

gdnrbob ,

Here is an excellent white paper on SPDs for you to read.
 http://www.p3-inc.com/images/surge_protection_device_systems.pdf

Here is another one on the importance of earth grounding.
http://www.p3-inc.com/images/grounding_for_pq_wp2016_p3.pdf
.

I installed an EP 2050 after a surge took out a Vandersteen amp....never had a problem since installation.....it actually had a benefit to the sound of the system.

Thanks everyone, it looks like this is more complicated than I thought.
Eric- your Home Depot link list many different units, did you have one in particular that you would recommend?
Jea48, thanks for the links, though they seem more geared to an industrial setting. 
It looks like the layered approach is the way to go. 
So, what do any of you recommend for the mains box?

Furman's claim to fame is their application to commercial or professional sound applications. They maintain nearly all of the market in professional sound reinforcement systems. Using the "guilt by association" model, one could draw the conclusion that if professional sound companies by a vast majority utilize and rely on Furman products to protect their systems, they will probably work for your home system as well. I'm not saying that their products will protect your system from a direct lightning strike but they are obviously reliable if they are the standard in professional applications. Let me make it clear that I have no affiliation with Furman whatsoever.