Yes, I know it's been discussed before and I have used the search function on here and DIYMA, but I'm looking for questions more directly related to my circumstances.
Over the next year or two, I will be slowly adding onto my system in a 2006 B6 VW Passat (without Dynaudio) which is currently bone stock. Next week I will be installing a Pioneer AVH-P8400BH (a step up from the AppRadio2 I was originally looking at). Main reason for this over a 80prs or 99 are the feature set as I am an avid iPhone user and have a jailbroken 4s, so I plan to take full advantage of App access on my head unit. After that (and depending on how much bday money I receive this year) I intend to deaden my doors, dash, and trunk with some RaaMat and Ensolite.
Following that I am looking at adding 1 or 2 subs to the back. Keep in mind I am strictly SQ, do not need/want to be heard more than 10 feet outside the car, but still want a good LF extension for the times I listen to trance and D&B. I'm hoping the sound opens up a bit with the head unit upgrade, but I'm worried that adding subs will overwhelm my stock speakers. After reading TONS of info about placement of subs I have decided I am comfortable with a box that is faced towards the split folding seats to avoid wave cancellation. I have no preference of sealed vs ported, though I would like to keep the box small enough to fit into the space underneath the rear deck to preserve storage space in my trunk.
Contenders are 2 Dayton 12" DVC HOs, 2 SA-8 D4v2s, and 2 SSA ICON 10" DVC 4ohm. All options would be wired down to 1 ohm and mated to a Sundown SAX-1200. I am flexible on amp options as well, but don't want this project to end up cost-prohibitive as I have to get WAF (wife-approval factor) on all decisions. Believe me, getting approval to upgrade the head unit was enough of a stretch.
Final stage of this upgrade would include HAT Clarus in the front and HAT Imagine running in coax in rear doors powered by a Zed Leviathan III if this helps shape the upgrade path.
Any recommendations and advice would be greatly appreciated.