There are many options and it can be difficult to identify the appropriate kit or products for your specific needs, but that is what we are here for. The kit normally purchased for this setup would be the A0915 kit. This kit comes with the 2 Gang in wall flush mount amplifier, iPod/iPhone dock, volume keypad, and a pair of speakers. However, you already have speakers so please just make sure they are 6-8 Ohm rated. Next, please be aware that due to manufacturing difficulties the dock for this kit has the older 30 pin style connector and has not yet been upgraded to the new Lightning connector used by 5th gen iPhone and up. You can purchase an adaptor from apple to convert this dock to a Lightning connector however so the option is still open and in the future we will release a field kit that you can upgrade the connector without replacing the whole dock. Since you have speakers you would just order the pieces individually instead of as a kit, A0350 amplifier, A0315 iPod/iPhone dock and the A0129 volume keypad. The remote control is sold separately as A0505.
Your other option would be to do a similar setup but instead of a dock use a wireless Bluetooth connection. This way it doesn’t matter what you have iPhone, iPad, computer, Android, Tablet, etc. Any device that can stream Bluetooth can connect audio to this unit. We also have a kit that uses all the same pieces but uses the AB-303 Bluetooth receiver in place of the dock and it doesn’t come with speakers. This kit is the A0919 Single Zone High Power Bluetooth Audio Kit. Again the remote control is sold separately as A0505.