I kind of got sidetracked on how I was going to fabricate the pieces, I started focusing on building a CNC router.
Now, I'm back to working on WALL-E. I went ahead an ordered some parts for the audio components such as a music shield, amplifier, and speakers. Audio will be stored on a microSD card and played through the music shield via a 3.5mm jack. I have that connected to the amplifier which powers 4 10-12 watt (RMS) speakers. I hooked it up and it doesn't sound too shabby. Until I get my hands on an oscilloscope, I don't want to push the speakers too much to the point it'll blow. The amp seems to be drawing about 200-300mA at the moment which isn't too bad since it's rated for a little above 3A.
As for my 3D model, I'm still working on the legs and the suspension. Once that's completed, I'm going to go back and re-work on the head - optimizing the components for weight, fabrication, construction, and maintenance. This goes the same for all the other components as well.
I'll still be working but my updates will be less of a daily thing and perhaps more of a weekly update.