For HSU, most likely you will have to order the sub you want and test it out, you have time to send it back and get a full refund...
I was in your position not long ago, I listened to everything I could get my hands on, sent a few speakers back, and ended up with
Ascend 340 fronts and ascent 200 surrounds, for the sub I got a vtf2 from HSU.. I spent around $1800 on the 5.1 before electronics, but I have heard systems 3 times that cost that can not touch what I have in volume, clarity, warmth, ect.... The HSU vtf2 fills my room with sounc effortlessly, I have it turned way down and it will shake my house apart...