PA 1100.5 amp with MM1040-DVC sub?

I am completely new to the audio sound system game and know pretty much nothing about it. Someone helped me set up my system.

I have a PA 1100.5 amp and was told that a Polk MM1040-DVC sub would work great on that amps sub channel for the rock music that I listen to. That it would pull 2 ohms, or about 300-400 watts. I often like to crank the music to about 75% of the head units volume. But I was told by Polk techs that I wouldn't wanna set the gain on the sub to anymore than just past halfway, or about 1 o'clock on the dial. For me that's not quite enough thump unless I were able to turn the gain up most all the way and I wonder why spending that much money on an amp you can only turn it up to only just over halfway? Seems like a waste of money to me.

I thought about getting 2 MM1040-DVC sub, but then Polk techs tell me that it would pull 1 ohm load (which this amp is set up to do), but then each sub would only get about 280 watts and that's too low for those subs & that could hurt them.

So it seems like I will blow my single MM1040-DVC if I turn the gain up past 1 o'clock on the dial, which at that setting isn't quite good enough for me on bass. But if I get 2 MM1040-DVC subs, the power they will each get will be too low and I could hurt them that way as well. I just don't know what to do.

Someone please help me here. I really wanna get this figured out.