Adding Sound

I am going to try to add sound to my project. I was looking at purchasing and adding it to my Mega. However my research has revealed that I will have to manually rewire it.

That being said, I am open to cheaper/easier options and I would like to know what pins I need to connect. Obviously I need the SPI pins, other than that, which ones do I need to attach? Can I attach it remotely rather than stacking it?

This tells you what pins it uses:-

Yes you can wire it up remotely.

Alternitave look at the AdaFruit wave shield.