In what format would the professional recordings be? On a CD?? What file format?? Do the professional recording people have any suggestions as to how their recordings can be interfaced to the system. Do they know how to change the bit rates to match the VM? Do they suggest just changing files on the VM? Have they done it before. Do they know how to change their format into the VM format?
Anyway--a lot of questions. I think that the time, effort and money invested to download a professional 30-45 second recording (or even more recordings) would be much too high.
If your customer has a script, they need to take it to a professional person (radio, TV, sound studio) and hire them to come to their place of business and do the voice recordings. I'm going to bet that would be cheaper & quicker. If the recording is a .wav file (Windows) I don't think it can ever be formated to the KeyVoice DOS file format. Maybe someone else has some other experience. Good Luck.