I, too, am a religious Pioneer fan. That's all I've ever had, and all I ever will. The internal tuning capabilities are outstanding... and the user interface is great. The Alpine, however, is still a great unit IF you're planning on external amplification and equalization. (IMO)
Enough ranting. If it were me, I'd go with November's ideas. Actually, many Pioneer units already have auxilary input, deleting the need for the bus unit. Controlling the sound of the music is far more important to me than being able to control the IPOD.