I'm a dealer with Furman, I use them all the time when I do installs.I've talked to their tech's a few times about the diffrent types of conditioners and applications. The main diffrence in their conditioner is how much of a hit they can take. Basically a lightning strike. So what I mean is how much do you want to protect your equipment.
Also, Their is always fluxuating current coming into your home. The conditioner regulates it as well. Because after time, your unit takes a beating throughout the components. TV, DVD etc.
When I do installs, and it's a big setup, I use the PL-8 Pro series II, if not an M-8 will work.
Front of house I use the ML-8(Lights),amp rack I use M-8. These are 15 amp units, regular plug. But if you get the 20 Amp series, they use the new plug, with one prong at a 90 degree angle, just so you know.
And of course they have a unit that displays the power that is being used, which is helpfull doing live gigs.
Hope this helps