Arduino or Raspberry Pi for my project A brief description of what I'm doing here. I wanna make a pet project, basically a device (be it Arduino or raspberry pi) that I can connect to via bluetooth / wifi (both preferably), that will be connected to a stereo system and allow me to play music. I essentially want to make a wireless sound system in my house.

My question is, is raspberry pi more adequate for my needs? Or would arduino get the job done? I know that raspberry pis are essentially mini computers, so I feel that the raspberry pi would be too much, since all I really need to do is design a bluetooth / wifi interface and send the signal to the aux cable connected to the stereo.

Any help would be really useful here. I've never worked with either/or, and this is my first project with Arduino / Raspberry pi (hello world). Thanks in advance.

EDIT: In response to comments below, a greater idea of what I want to do:

I want to design an item that will appear on local wifi as a sound device. i.e. on an imac / macbook I'd be able to right click on the speaker icon in the upper right and select it there). From there, I'm hoping to stream audio to the device, and have it play to a stereo that the arduino / raspberry pi would be connected to. I'd love to make this universal (i.e. possible to connect via your android phone / a windows machine), but I can imagine that part being a lot more difficult. I'd also like to add bluetooth functionality at some point, but that'd be in the future. Hopefully this gives everybody more of an idea of what I'd like to achieve here! I appreciate all the help so far.
As mentioned in the comments, a Raspberry Pi would be superior here.

The standard AVR (not Due/Galileo/Yun) Arduino is superior to the Pi in only one area: IO. It has a 5V logic that's more compatible than the Pi's 3.3V (although you can use a logic level shifter). The Arduino also features more PWM pins and an ADC, along with interrupts. An Arduino also is a lot simpler to use for basic projects, but it becomes impractical when you need more computing power.

A Pi excels at the data-crunching side of things. It can handle a lot more data than the Arduino could ever dream of, and then some! Just to put things in perspective, the Pi has a clock speed of 700 MHz by default and the Arduino Uno has one of 16 MHz (with a less powerful architecture).

For your purpose, the Pi's audio jack and ethernet port are unmatched on the Arduino. Sure, you can get shields that replicate these behaviors, but the Pi's built in functionality doesn't cost extra and it's more powerful.