I will repeat my question. What do you hope to accomplish? Surge protection? Noise reduction? They are two different things.
FWIW when you see things like "80 dB" they are probably talking about noise reduction. The question you need to answer for yourself is "Do I need powerline noise reduction?" I and many others here don't think we need it. The power supplies in most electronic gear are very good at making sure that power line noise does not significantly affect the proper operation of the gear.
Monster's "stages" are IMHO a little more than a way of confusing consumers. There is no industry standard for what capability is in what stage, so it is impossible to compare between manufacturers unless you look at what is actually included.
As far as surge protection goes, the primary things that are relevant are the UL 1449 3rd Ed. Voltage Protection Rating (VPR) and the maximum surge current the device will handle. The lower the VPR, the better. Just keep in mind that just about all electronic devices are inherently immune to surges up to at least 600V. And if you are considering a point-of-use surge protective device, the maximum surge current rating isn't an issue for name brand devices, except as a measure of potential life time, because the worse case expected surge is only about 90J.
I guess I should mention that the need for surge protection is highly over-hyped, filtering even more so.
And BTW having surge protection on your AC lines is not necessarily sufficient to prevent damage from surges. All conductive paths into your gear, like cable, antenna, LAN, phone line, etc. also need to be appropriately protected.