http://www.sonicelectronix.com/item_17121_Precision+Power+PPI+356CS.html
http://www.shopatron.com/products/productdetail/part_number=KS%20300.2/1735.0.55639.0.0.0.0
There's $440 with $60 left to spare for some wire.
Oops, didn't realize you need power for the sub too. You'll need 4 channel...