Some help with iPhone cable choice and install

[AZCanna]

After searching the forums for the best solution for playing and charging an iphone, I've decided that hooking into the back of my cdr-220 is how I want to go. What I haven't found is a satisfactory answer as to which of these two cables to go with.

iP-BKR3 iPod and Aux Adapter for Becker Radios with "AUX" Menu Option :: iPod Adapters & Interfaces :: Discount Car Stereo
iP-BKR2 iPod Adapter for Becker Radios with "AUX" Menu option :: iPod Adapters & Interfaces :: Discount Car Stereo

My gut instinct is to just get the BKR3, but will i use the other analog connection? Im sure that there are folks here who've used both...any advice/reviews appreciated.

thanks.