Great Lakes Garrison & Base

I bought a speaker shirt with a remote control for my Chewbacca costume. The control has an SD card slot that I loaded with Wookiee sound effects (some of you saw it at a couple of events). I love the remote control feature, but I'm afraid the speaker is not loud enough.
Is it possible to take the wire out of here:


and rig it up with an audio jack like this:


There is a Radio Shack by my house, but I thought I'd ask if anyone knew if I could do this or what I would need before I rolled in and totally confused the goober at the store.
Thanks

You can buy the amp from Radio Shack and hard wire the speakers to it. You have to pull apart the amp case, but you can solder them directly to the speaker in the amp. It has the jacks on the side of it to plug in your sounds.

It's totally possible to get the jack you need from Radio Shack. Don't ask the people that work there, because they will usually tell you the wrong thing at the Chesterfield store. What you are looking for is in the parts drawers at the back of the store, a 1/8" Phone Plug (2-Pack) Model: 274-287. They are $2.99. If you need some soldering help, let me know.