Ok Crazy Idea.... So my friend and I are building "Party Briefcases"

So first it started with brief cases with insulation to hold our beers, then with the addition of small speakers an explosion of Idea's came out for our briefcases. Currently I'm planning on wiring and old mp3 player to a cheap battery operated portable stereo and wiring some car speakers 5x9's too them. Knowing only the basics of electronics I was just curious of any input on this project of ours. Suggestions, comments, other ideas, and/or anything else you wanted to spat at me.

You mean something like this? **broken link removed**

No A its not wood and vinyl like our brief cases, B it does not have a 20gb hard drive attached to it, C its just gay and this is cool!

My friend is far better at this than me he had his attached to his guitar unfortunately he blew the speakers, hints why we need speakers that can hold up better. I figure there isn't enough juice in a portable stereo to blow out two 5x9's!

I want to connect my creative zen touch to a portable stereo. I want to pull the sound out of the usb and power it with the dc in 5v. Any suggestions.