I am staying in a small town here which you could hardly find a Sub like SVS or HSU.
The most i can find is listed below:

JBL E250
JBL PB12
Velodyne VX 10
PSB Subsonic 5

However these equipments are quite expensive in my country. Any one of these would cost me over $300! All the big brothers out there, plz advice which one of those u prefer.
I don't really like boomy sound, i'd rather go for something which really goes 30Hz and below. I've gone through some good reviews on the JBL E250, saying that it is a great improvement for JBL. How would u grade it if compared to the rest listed above?

Thanks for the advice!