Car audio is the least of my worrys - but here is my 2cents. I really cannot umderstand spending 4-5 grand on a sound system (unless your entering it into competitions). From what your after, sounds like you can really crank it - but arent you gonna have mates in the car - are you the type of people that pump music at a volume that is over the top? Myself personally- whenever i have a passnger the music is not loud at all. How rarely do you drive by yourself?

If
You are looking at getting an audio upgrade.

My suggestion is to get a decent headunit. I got a type s and yes the speakers feel shit. I upgraded my headunit and the sound system is quite adequeate. There is bass and treblenfound.