I went Pinbox because I don’t like worrying about proprietary hard to come by parts. Also swapping out the original computer and monitor provided a substantial weight reduction.
I used a Dell Optiplex 380 SFF. Onboard audio worked fine with a 2.93ghz C2D processor. 120GB SSD and 3GB ram.
I had an Athlon X2 as well but the audio was choppy with that even with the addition of a Sound Blaster Live!