what I meant about total control of your sound..... some HU have a basic 3 band equalizer and some get more in depth, for example back in 2003 I had the Kenwood KDC-X969 which allowed you to control the Q factor of the sound to achieve the perfect sound for your car, what I am asking is, how much control do you want of the sound, do you want just the basic Treble/MID/Bass controls or are you needing more? for example this is what my old Kenwood deck would allow you to control.....
" In addition, you may store your own settings under the "User Memory" EQ curve. Each preset has its own bass center frequency, bass level, bass Q factor, bass extension, middle center frequency, middle level, middle Q factor, treble center frequency, and treble level settings. You may adjust the bass center frequency (60, 70, 80, 100 or 150Hz), bass level (-8 to +8), bass Q factor (1.00, 1.25, 1.50 or 2.00), bass extension (On or Off), middle center frequency (0.5, 1.0, 1.5 or 2.0kHz), middle level (-8 to +8), middle Q factor (1.0 or 2.0), treble center frequency (10.0, 12.5, 15.0 or 17.5kHz), and treble level (-8 to +8). "
So you would like an IPOD device to be an option, how about HD radio. I have HD radio and I will not listen to regular FM anymore, the sound is just that great especially since the SAT companies are going with more content vs better quality. I am not trying to push HD radio, just giving you an idea on what is out there. Also there are a couple of HU on the market that read DVD-R's which will allow you to put 4.7 GB of mp3/wma on a single disk.