I'm kinda looking for a Pioneer(840 or higher)/Alpine(9831 or higher) deck, and not too familiar with them. What are the options/features for these decks that set them apart from a cheaper deck, and what are some things that I will notice most. I have an amp powering my 4 speakers already, so I guess I don't have to worry about the internal amp power on the decks, so what features are going to benefit my setup most?

 

high voltage preouts