client self generated invoices

Hi, I want to setup a business that allows clients to fill out a form to request an invoice from me.

Let me explain that better, in Mexico, businesss need to start providing digital invoices for their clients by the end of the year. The softwares to do that are quite expensive, so I have bought a copy of a software that does that, and right now im providing the service for offline clients to generate this digital invoices for my clients clients using this software.

What I want to be able to do is to expand this business so “registered” clients can fill out a form (much in the saw way wp-invoice can add remove items in an invoice) of the “sale & products” they just made, I get that “request” with all the info, copy/paste that into my system, generate an “official approved invoice in pdf” and then I will put the generated xml/pdf file for them to download somewhere.

I know is a very specific question, but I thank you in advance for your reply.

Regards,

Jorge

http://ww.wp.xz.cn/extend/plugins/wp-invoice/