Create multiple invoices through customer group "custom field" selection

My small request is that after the user creates a “custom field” in the customer record, he have the ability to use this custom field for selection criteria to create a batch set of invoices. Please allow me to give you an example.

I might call my custom field “Customer Type”. A drop down menu might appear and the options might be “Tier One” and the second option in the drop down might be “Tier Two”. I would initiate a ‘Create batch Invoices’ based on using the custom field for selection criteria and I would then be able to select all of the customer in the database with the custom property of “Tier Two”. The invoice window would appear with the customer field greyed out. I would be able to put in an amount in that invoice and so with a single entry would apply to everyone in that selection group. I would then be able to email to everyone in that group with a single keystroke.