we use vBulletin as our forum and had to do a lot of customization work to get it functioning, it was not a simple out of the box up and running situation.
The login username doesn't have to be how the user is identified in the forum. Our own system uses email address, and email verification, but does not show the email address in the forum. (A double opt in tutorial is on the way....)
If you are not comfortable with custom coding, i would not recommend trying this, or we could assist you in a premiere support appointment.