I own an 2002 GMC Sonoma SLS. The audio system inside is a little dated only having a cd and a radio, and when I drive I like to listen to my Ipod. I have grown tired of the radio transmitter always failing so I am switching out my audio system for an upgraded one with an AUX jack. I am also swapping out the 4 speakers. I believe the dash speakers(2) are 4x6 and the door speakers(2) are 6.5". What are your suggestions of speaker brand/type and for the main audio hub as well?