Iv got a clarion HU which plays mp3s and windows media which is quality, has a built in sub control too so u can decide for yourself how u want it set up. Also means you can fit a sh!t load of tunes on one CD...many thanks.
More important tho is gettin a quality amp. I have a genisis P4 ultra and it is amazing!I had a shockin amp in my last car with the same sub i have now and it sounded nothin like as good. got a vibe black air 12" btw.
In general, the more u spend the better u get.