Hello
I thought this might help;
as the Paraliminals are Holosync technology based, I've been told by Holosync that the best frequency headphones are around 5 Hz. They've recommended these ones:
http://specials.centerpointe.com/cri-300/If you wish to buy a different brand, i researched this a lot & found most of the ones that go as low as 5 Hz frequency are quite expensive as they tend to be professional DJ ones but these had particularly good reviews:
KRK KNS 8400 bk
They also recommend Sleepphones which you can buy on Amazon or from centerpointe.com
