You should be able to get either of those for a decent deal since they are last year's models. The new line-up are the AVH-X series (4500, 5500, 8500). There is not a whole lot of difference between them but if you are an android user, you will definitely want the AVH-X series so you can stream pandora and also stream music stored on your phone. The AVH-P series is not android compatible with pandora. The 8400 (or 8500 in the new series) have a detachable face and the ap mode on the 8500 will work with android, not just iPhone.