Wow, congrats... I would love to hear how it sounds. I am in the process of planning out what changes to make, the only thing I am a bit concerned about is vibrations... E36's are notorious for vibrations with aftermarket systems. How is yours doing with those mods?
The only thing I have besides the stock system is a 6disk mp3/cd changer and a Kenwood 300watt amp and 8" Bazooka tube. Which is filtered to just lay in the really deep lows. It helps quite a bit, but the whole system could use a boost.
The key thing for me is being able to wire in my iPod, I am going with this
Alpine 9855 for the head unit.
Now I just need to figure out how to lay out my speakers now... Your set up sounds really close to what I had in mind.
Cheers,
Gadget