create a 30 second video animation based on voice

Hi, I got a client that needs a 30 second animation customized to the voice sample he would be providing to me. The video should be animated in a creative way describing how the free service on my client's website works. The video has to describe the process of signing in on to the website (using screenshots) and also give an outline of its functionality. Logo, 30 second voiceover and website address shall be given along with other instructions to the winning bidder. the video SHOULD follow with the voiceover narration. Kindly note that it is a simple task for just 30 seconds. So please, i want realistic bids and timeframe, and do not forget to attach your relevant samples so that i may gauge your skills and select you. Payment via freelancer milestone only.