Have contacts consisting of service providers and prospective clients. Need to assign prospective clients to a particular service provider. Then, need to be able see views/reports sorted by providers, provder’s city/state, etc. Then, need to be able to easily send out invoices or Status Reports to the Service Providers. For example:
Have 100 consultants (service providers). Periodically, I get people who need consulting. I match them up with consultants. I charge consultants a small fee for the referral. So, I need to easily track the relationships and be able to send correspondence to the consultants – either an invoice or a "referral activity" report showing them who they’ve been assigned. Correspondence will need to be via email, fax or mail.

I am not looking for any service provider like efax and other; but how is it possible to do it from Wireless internet?

Do fax machines work more like e-mail, where you can send as many as you want regardless of the destination for the same price of the service provider. Or is it more like calling someone on the phone, where one is charged by the destination and and time spent.