I couldnt not find it to buy from anywhere at all, and that is why I ended up making it myself. There have been a couple previously but have finished on a popular auction site (seach for "computer case speaker"), but no current auctions for one.
Just like you, I had no idea where to start initially.
But had an old happymeal toy lying about. Just got a hacksaw and sawed it apart. Took the small speaker out (about 1" diameter)). Cut the 2 wires (black and red) that were connecting it to the circuit board in the toy. Then just temporarily held the 2 wires to the 2 mobo speakers pins while booting to listen to the beep codes.
It isnt really a permanent solution but fine if you just want to listen to a beep code, and then can disconnect it again. Just hack apart anything with a small speaker in that you dont need any more (small toys, headphones, earphones) and connect the speaker to the mobo pins, making sure to connect positive to positive, and negative to negative, and you should have no problem.
If you are still not comfortable doing this, try getting somebody else you know that is ok at electronics to make it for you as it really is very simple and takes seconds
