I am a noob, please help me!

[Sir_Swagelot]

So basically, I am looking to make a multipurpose raspberry pi to use as a mp3 player and an emulator. I want to be able to control it via a usb retro-style controller, and my raspberry pi will be using this (https://www.hifiberry.com/product/hifiberry-dacplus-phone/) as a sound card. I was wondering if I would be able to do this using xbian, and how hard it would be. Preferably, I could use it as a sort of ipod shuffle, with no need for a screen. Will I able to swap it out between mp3 and emulator mode by using a different boot device easily? Any and all help is greatly appreciated, as I am a complete noob. Thank you!