I have a Massive Audio N3 Class D mono block sub amp 700w 2 ohm and stable down to 1/2 ohm, it is a little bit more power then you are looking for, and not quite enough for my needs (I went with a 4 ohm set up), but small as heck. It has been hooked up and played with, but is nice and minty and in the box for $200 shipped CONUS only.