I bought a speaker/subwoofer combo at the local Fry's Electronics for only $14.99!! Funny thing is that when I was comparing the sound quality in the store, these speakers sounded the best. They just happen to cost the least. BONUS!

I had them apart in no time. The actual speakers are pretty small, but they should work fine for starters. I'm planning on mounting the power/volume board in the cabinet below the control panel. It looks like I'll have to get a soldering iron!
Update: Borrowed a soldering iron from a buddy and got everything disconnected so I could remove the speaker enclosures from the speakers. I left the sub-woofer intact. I then soldered some of the "bell" wire I got for the control panel wiring and made some longer speaker cables.

Here is a picture from above the cabinet looking down. I removed the back angle-panel so you can see down into the top. You can see the 2 speakers on each side mounted over the speaker openings with the black craft-felt inbetween the speaker and the wood. I took the subwoofer and screwed it directly between the two main speakers. I figured that this is would be the best place to get the most sound out of the subwoofer to the players ears.

This picture shows the sound on/off and volume controls. I was able to reuse part of the plastic casing from one of the speakers to make this look half-presentable.