i have the kenwood mp919, and i ****ing love it!. its got everything you need and more. mp3 decoding, an optional aux input, 4.5 volt preouts (3 sets of em), sirius radio ready, and tons of sound-tweaking options. i have no complaints on this thing at all. sounds awesome, and it looks nice too. I used to have a sony HU and it lasted less than a year. I would reccommend staying away from Sony brand car audio products.
edit: ok i have one complaint i guess: the remote is too big....but I've learned to live without it.