Each agent and publisher will have their own submission guidelines, and many do accept electronic submissions. I don't know of any, however, who will take phone calls from new authors who have never been published. You'll most likely end up with a message left with a receptionist somewhere.

I would recommend starting out with agents by sending a link to your electronic file. (Sending the actual file may clutter their Inbox, and some companies block large files to open e-mail addresses to prevent e-mail server attacks. Again, the submission guidelines will most likely help you with this.) If an agent decides that your book has potential, they will be better positioned to suggest how to proceed from there. They would have a better idea as to whether you should try to promote the current story with the existing illustrations or go with just the story itself.

BTW - I did a Google seacrh on "find and agent", and the first couple of links were to searchable databases that were free. This might be a good place to start.