Most all receivers have iPod capability the question is the extent to which the capability extends. Some receivers have a dock where you can control the iPod via remote or you could do what I do and get an headphone to analog cable and plug it into your receiver. I just have to control the play options via ipod.
As for most music enchancement I dont use mp3s, they are just too lossy .wma or the macs version of the same, flac, are losseless. Most of the time I would say music enchancement is not the greatest anways, why would you want to change the music from its oringal recording anyways.