I am sure you are familiar with HSU and SVS subs as well, here are a couple of their offerings for a little less than the EP350. Just to make choosing a more difficult affair...

For the HSU STF3 ($599.00 USD+ 53.00 s/h):
http://www.hsustore.com/stf3.html

For SVS PB12NSD ($599.00 USD):
http://www.svsound.com/products-sub-box-pb12nsd.cfm


M80ti's, VP150, QS8's