tojo_m - have you taken a look at the Fosgate 3SIXTY.3? I know the inclusion of one will blow your initial budget, but that's the route that I'm probably going to go.
There is a great shop up in Prescott called Audio Plus. It's definitely a drive, but could be quite worthwhile. They're one of the only Paradigm suppliers in the state, so that's how I got to know them. Anyway, their prices were reasonable and the staff is certainly willing to work with you. Give them a call and ask for Brent; he's a great guy and very helpful. They are an authorized Fosgate dealer. I'll probably be going to them for the aftermarket gear for my MSport when it arrives.
Be sure to let us know about whatever experience you have.
2013 335 M-Sport | BSM | Blk/Blk/AlumHex| 6MT | Premium | Technology | Cold Weather | Driver Assistance | Dynamic Handling | Harman Kardon | ED 9/6