Need help on picking a system

I have a 01 Navigator with the 3rd and I want to keep the seats back there but i what to find something that will fit nice back there but also beat hard.

Well some info would be nice im assuming you are talking about a 3rd row of seats. NOt sure on space but since the things are so damn big there should be a bit of room in the back. Next thing you need is a budget, what kind of music and how much bass you want.

^ yup that info is needed, but hey ima throw this out there...and I have a feeling it will work. 2 RE SE 15's 5.5-6 cbft tuned to 30hz 1 RE 12.1 amp and call it a day for your substage. WHAT YOU GOT UP FRONT!?