I need help setting up Two Reference power conditioner 20Is on the same circuit

I have TEN Anthem Monoblocks M1s I need protected for my Home theater. I have 20amp GFI Recepticle Circut. 

That's a lot of amplifiers.  Ten 1,000 watt monoblocks.  I would not advise hooking all of them to one 20A circuit.  There is a huge risk of over-draw and possible fire at this point.  I don't know the current draw, and the M1 are Class D amps, but there is going to be an idle current.  On normal Class AB amps, it's typically 65 watts to 150 watts.  On Class D, let's assume 50 watts (but possibly more on the 1,000 watt M1).  So, ten amplifiers at 50 watt idle means you're drawing 500 watts constant.  If you get any loud music/movie scenes, you could definitely over-draw that 20A circuit.  If each amp draws 200 watts (which is definitely possible because even Class D amps are only about 80% efficient on average), you're looking at hitting the 2,000 watt point pretty easily.

If you ever see those fire fighting movie/television shows where the people are plugging in like 20 computers into 4-5 chained power strips, this is exactly what you are doing here.

With Class D, I would not connect more than 4 of the M1 amps to a 20A circuit (I would only connect two to a 20A circuit if you plan on cranking them past 50% loudness).  So, I would highly advise putting in a minimum of 3 or 4 20A circuits using 10awg Romex wiring for each circuit.  You could use a double-outlet box (4 plugs) for a each circuit.

I have experienced another side effect of connecting multiple audio equipment to the same plug/circuit.  Because of the high constant draw, this constant draw of amplifiers could affect each other and cause a slow-down of fast current draws for high frequency transients.  This results in a slow and warmer sound that doesn't have the resolution and attack and impact that you would normally hear.