I want to upgrade my Monsoon and kick it up a notch. I'll start with a rear drivers side sub and mono amp. I'm leaning towards a JL Audio 10 inch sub, which model W7? Which sub-box, custom fiberglass? They are expensive, how about the $112.00 sub-thump box? How about the mono amp, JL Audio or Alpine V12? Anyone have Focal sub? How about replacing the stock speakers, more JL Audio? I have a brand new Phoenix-Gold 4-channel amp, is this suitable to drive the rest of the new speakers? Advice appreciated.