Smartphone with additional peripherals

I need to make a smartphone like device with some additional peripherals like ethernet , some application specific interfaces.
Device should run android on it, it should have SIM in it, internet connectivity, camera also, usb connectivity on PC , touchscreen , speaker; basically all features of mid segment smartphone.

For addional peripherals, which are to be handled by apps in android, I am planning a separate board for them which will interact with beagle board(which is running android) via some comminication protocol.

How should I proceed?

I had checked , but its further link don’t get opened.

Which board should I select?