I think the best ones for a room of that size is either the EP500 or the HSU. The EP350 would also work very well but doesn't reach as low as the other 2. I had the PB12-nsd and it has plenty of punch, a little too much for my tastes in the 50-60 hz range. I had to move it around the room a little to even things out. The other subs I have tried, EP350/500 and my current PB13- Ultra worked very well and were smooth right out of the box and no extra positioning was required.
I was very impressed by the EP500 when I heard it, lots of good HT power for such a small package and it was great with music as are all the EP subs I have heard.
