Finalize an explainer video with voice-over

I already have a Camtasia project with all needed files (pics, script, etc...). I need a professional touch to bring the explainer video to life. A sample narration is included in the project.

If you prefer to use your own video editing software, I can also send needed media files (pics, scripts, etc...) if you don't like to work with Camtasia.

You can see the current video here:
http://www.youtube.com/watch?v=tLDHMRupyRw

I'm looking for someone to polish the video, add voice-over, transitions, sounds (where needed on transations). Expected final video to be something of this quality:
http://www.youtube.com/watch?v=Sm-YFNiIGVQ